Medium chain length polyhydroxyalkanoates and their use in chewing gum bases

Abstract

The present disclosure relates to medium chain length polyhydroxyalkanoate (mcl-PHA) copolymers and chewing gum bases and chewing gums comprising the mcl-PHA copolymers. In some cases, the mcl-PHA copolymers can partially or completely replace conventional petroleum-based gum base polymers, including elastomers, in chewing gum and gum bases. The chewing gum and gum base of the present disclosure may be free of or substantially free of petroleum-based ingredients. Compared to conventional chewing gum, chewing gums comprising the mcl-PHA copolymers of the present disclosure may also have enhanced degradability.

Description

Technical Field

[0001] The present disclosure relates to chewing gum base and chewing gum. More specifically, the present disclosure relates to improved formulations of chewing gum base and chewing gum containing medium chain length polyhydroxyalkanoate (mcl-PHA) copolymers. Background Art

[0002] The basic components of chewing gum are usually water-insoluble gum base parts and water-soluble bulking agent parts. The main component of gum base is an elastomeric polymer that provides characteristic chewy texture for the product. Gum base usually includes other ingredients that change chewing characteristics or help to process products. These ingredients include plasticizers, softeners, fillers, emulsifiers, plastic resins and colorants and antioxidants. The water-soluble part of chewing gum usually includes bulking agent and a small amount of minor components such as flavorings, high-intensity sweeteners, coloring agents, water-soluble softeners, chewing gum emulsifiers, acidulants and sensitizers. Usually, the water-soluble part, sensitizers and flavorings dissipate during chewing, and the gum base is retained in the mouth during the whole chewing process to produce a chewing gum cud.

[0003] Traditional chewing gum base is mainly made of polymer derived from petroleum raw materials. For example, butyl rubber is derived from petrochemicals. The advantage of doing this is that the polymer remains consistent over time, and when making the polymer, the desired property in the chewing gum can be taken into account to realize the desired chewing characteristics of the chewing gum product. However, since oil is a gradually decreasing resource, its supply is vulnerable to destruction, and the source quantity of the food-grade polymer derived therefrom can be obtained to be limited, so the butyl rubber substitute can alleviate the dependence on petrochemicals, and produce the innovative gum base using non-petroleum-based materials. In addition, although chicle and other naturally occurring polymers were used to make chewing gum in the past, the polymer coming from natural sources tends to have the most common characteristics of fluctuations with the seasons of the year. This makes it difficult to consistently prepare high-quality chewing gum products.

[0004]

[0006] It would therefore be desirable to provide a chewing gum base that can be made from renewable resources (ie, not petroleum-based) but that also provides the desired texture, mouthfeel and other chewing characteristics to the chewing gum. Summary of the invention

[0005] In one aspect, the present disclosure relates to medium chain length polyhydroxyalkanoate (mcl-PHA) copolymers and chewing gum bases and chewing gums containing the mcl-PHA copolymers. In some cases, the mcl-PHA copolymers of the present disclosure can partially or completely replace conventional petroleum-based gum base polymers, including elastomers, in chewing gum and gum bases. Therefore, in one case, the chewing gum and gum base of the present disclosure do not contain or are substantially free of petroleum-based components. Advantageously, the mcl-PHA copolymers of the present disclosure have better physical stability than previously known PHAs. Compared to conventional chewing gum, chewing gums containing the mcl-PHA copolymers of the present disclosure may also have enhanced degradability.

[0006] Thus, in one aspect, the present disclosure relates to a medium chain length polyhydroxyalkanoate (mcl-PHA) copolymer comprising repeating units of at least three different hydroxyalkanoate monomers, wherein each hydroxyalkanoate monomer has a C3-C 30 Alkyl side chain.

[0007] In one instance, the mcl-PHA copolymers of the present disclosure comprise repeating units of three different hydroxyalkanoate monomers.

[0008] In one instance, the mcl-PHA copolymers of the present disclosure comprise repeating units of at least four different hydroxyalkanoate monomers.

[0009] In one instance, the mcl-PHA copolymers of the present disclosure comprise repeating units of four different hydroxyalkanoate monomers.

[0010] In one instance, each repeating unit in the mcl-PHA copolymer of the present disclosure is independently a repeating unit of formula (I):

[0011]

[0012] Where: R is C3-C 30 alkyl; m is 0, 1, 2 or 3; and n is an integer from 1 to 32. In one embodiment, m is 1. In one embodiment, R is C3-C 15 In one embodiment, R is C3-C 11 In one embodiment, R is a C3-C9 alkyl. In one embodiment, n is an integer from 1 to 24. In one embodiment, n is an integer from 1 to 16. In one embodiment, n is an integer from 1 to 3.

[0013] In one instance, the mcl-PHA copolymer of the present disclosure comprises repeating units of at least three different hydroxyalkanoate monomers, wherein the hydroxyalkanoate monomers are selected from 3-hydroxyhexanoate, 3-hydroxyheptanoate, 3-hydroxyoctanoate, 3-hydroxynonanoate, 3-hydroxydecanoate, 3-hydroxyundecanoate, 3-hydroxydodecanoate, 3-hydroxytridecanoate, 3-hydroxytetradecanoate, and combinations thereof. In one embodiment, the hydroxyalkanoate monomers include 3-hydroxyhexanoate, 3-hydroxyoctanoate, 3-hydroxydecanoate, and 3-hydroxydodecanoate.

[0014] In one instance, the mcl-PHA copolymer of the present disclosure comprises from about 8 mol % to about 19 mol % 3-hydroxyhexanoate.

[0015] In one instance, the mcl-PHA copolymer of the present disclosure comprises from about 32 mol % to about 65 mol % 3-hydroxyoctanoate.

[0016] In one instance, the mcl-PHA copolymer of the present disclosure comprises from about 20 mol % to about 40 mol % 3-hydroxydecanoate.

[0017] In one instance, the mcl-PHA copolymer of the present disclosure comprises at least 0.5 mol % 3-hydroxydodecanoate.

[0018] In one instance, the mcl-PHA copolymer of the present disclosure comprises at least 7 mol % 3-hydroxydodecanoate.

[0019] In one instance, the mcl-PHA copolymer of the present disclosure comprises at least 10 mole % of 3-hydroxydodecanoate.

[0020] In one instance, the mcl-PHA copolymer of the present disclosure comprises from about 7 mol % to about 12 mol % 3-hydroxydodecanoate.

[0021] In one aspect, the mcl-PHA copolymers of the present disclosure are random copolymers.

[0022] In one instance, the mcl-PHA copolymers of the present disclosure are nanodomain block copolymers.

[0023] In one instance, the mcl-PHA copolymers of the present disclosure contain from about 350 to about 7000 monomers.

[0024] In one instance, the mcl-PHA copolymers of the present disclosure have a major monomer content of about 97 mol % or less.

[0025] In one instance, the mcl-PHA copolymers of the present disclosure have a major monomer content of about 50 mol % or less.

[0026] In one instance, the mcl-PHA copolymers of the present disclosure have a secondary monomer content of at least 0.5 mole % for each secondary monomer.

[0027] In one instance, the mcl-PHA copolymers of the present disclosure have a secondary monomer content of at least 10 mole percent for each secondary monomer.

[0028] In one embodiment, the mcl-PHA copolymers of the present disclosure have a glass transition temperature (T ) of about 37° C. or less. g ).

[0029] In one embodiment, the mcl-PHA copolymers of the present disclosure have a glass transition temperature (T) of about -20°C to about -45°C. g ).

[0030] In one embodiment, the mcl-PHA copolymers of the present disclosure have a crystalline melting point (T m ).

[0031] In one embodiment, the mcl-PHA copolymers of the present disclosure have a crystalline melting point (T m ).

[0032] In one instance, the mcl-PHA copolymers of the present disclosure have a crystalline heat of fusion (ΔHm) of about 35 J / g or less.

[0033] In one instance, the mcl-PHA copolymers of the present disclosure have a crystalline heat of fusion (ΔHm) of about 20 J / g or less.

[0034] In one embodiment, the mcl-PHA copolymer of the present disclosure has a viscosity of about 1 x 10 3 dyn / cm 2 About 1x10 7 dyn / cm 2 Complex shear modulus (G*).

[0035] In one embodiment, the mcl-PHA copolymers of the present disclosure have a molecular weight of about 2 x 10 4 dyn / cm 2 About 2x 10 5 dyn / cm 2 The complex shear modulus (G * ).

[0036] In one instance, the mcl-PHA copolymers of the present disclosure have a number average molecular weight of about 50,000 g / mole to about 1,000,000 g / mole.

[0037] In one instance, the mcl-PHA copolymers of the present disclosure have a number average molecular weight of about 79,000 g / mole to about 104,000 g / mole.

[0038] In one instance, the mcl-PHA copolymers of the present disclosure have a weight average molecular weight of about 100,000 g / mole to about 1,000,000 g / mole.

[0039] In one instance, the mcl-PHA copolymers of the present disclosure have a weight average molecular weight of about 150,000 g / mole to about 218,000 g / mole.

[0040] In one embodiment, the mcl-PHA copolymer of the present disclosure has a viscosity of about 1 x 10 4 Pa-s is about 7x10 4 Complex viscosity (*η) in Pa-s.

[0041] In one aspect, the present disclosure is directed to a chewing gum base comprising the mcl-PHA copolymer of the present disclosure.

[0042] In one instance, the chewing gum base of the present disclosure comprises at least 20% by weight of the mcl-PHA copolymer.

[0043] In one instance, the chewing gum base of the present disclosure comprises about 40 wt % to about 70 wt % of the mcl-PHA copolymer.

[0044] In one instance, the chewing gum base of the present disclosure comprises the mcl-PHA copolymer and further comprises at least one additional non-petroleum-based ingredient selected from fillers, minerals, fats, emulsifiers, natural waxes, and combinations thereof.

[0045] In one instance, the chewing gum base of the present disclosure comprises the mcl-PHA copolymer and further comprises at least 1 wt % of at least one additional non-petroleum based ingredient.

[0046] In one instance, the chewing gum base of the present disclosure comprises the mcl-PHA copolymer and further comprises about 30 wt % or less of a petroleum-based polymer.

[0047] In one aspect, the chewing gum base of the present disclosure does not contain petroleum-based polymers. In one aspect, the petroleum-based polymer is selected from butyl rubber, polyisobutylene, butadiene-styrene copolymer, vinyl polymer elastomer, polybutadiene, polyterpene resin and combinations thereof.

[0048] In one instance, the chewing gum base of the present disclosure comprises the mcl-PHA copolymer and further comprises 10 wt% or less of a tackifier. In one instance, the chewing gum base of the present disclosure comprises about 5 wt% or less of a tackifier.

[0049] In one aspect, the present disclosure is directed to a chewing gum comprising at least one sweetener, at least one flavoring agent and the chewing gum base of the present disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] Figure 1 is a graph showing the complex shear modulus (G*) of the mcl-PHA copolymer of the present disclosure (FBF-4, see Example 1) compared to butyl rubber and a commercially available chewing gum base (Comparative Example 1).

[0051] Figure 2 is a graph showing the complex viscosity of a gum base containing the mcl-PHA copolymer of the present disclosure (Example 2) compared to three commercially available gum bases (Comparative Examples 1-3).

[0052] Figure 3 is a graph showing various rheological properties of a comparative gum cud containing polyhydroxycaprylate homopolymer immediately after formation and after storage at room temperature for 24 hours compared to the rheological properties of a typical gum cud. DETAILED DESCRIPTION

[0053] The present disclosure relates to medium chain length polyhydroxyalkanoate (mcl-PHA) copolymers and chewing gum bases and chewing gums comprising the mcl-PHA copolymers. In some cases, the mcl-PHA copolymers of the present disclosure can partially or completely replace conventional petroleum-based gum base polymers, including elastomers, in chewing gum and gum bases. Therefore, in one case, the chewing gum and gum base of the present disclosure can be free of or substantially free of petroleum-based components. Advantageously, the mcl-PHA copolymers of the present disclosure have better physical stability than previously known PHAs.

[0054] Medium chain length polyhydroxyalkanoate (mcl-PHA) copolymer

[0055] Polyhydroxyalkanoates (PHAs) may have a wide range of thermal and mechanical properties depending on their structure. Currently available PHAs tend to recrystallize over time. Therefore, including such PHAs in chewing gum bases may have a negative impact on the stability and chewing properties of the gum base (see, e.g., Comparative Example A). Specifically, as PHAs recrystallize, they become tough and unsuitable for use as gum base elastomers.

[0056] Without wishing to be bound by any theory, it is believed that the molecular stereoregularity of conventional PHAs (including homopolymers and copolymers comprising long uniform blocks of the same monomer) contributes to the recrystallization of PHAs over time. It has now been discovered that by altering certain properties of the PHA structure, PHAs with improved stability and chewing properties can be obtained. Specifically, by disrupting the molecular stereoregularity of the PHA polymer chain, PHAs with low crystallinity, low glass transition temperature, and low shear modulus can be obtained.

[0057] One way to achieve this is to form PHAs from hydroxyalkanoate monomers with bulky or long side chains. However, PHAs with long side chains may still be susceptible to side chain recrystallization over time. It has been found that medium side chain lengths are sufficient to disrupt molecular stereoregularity (e.g., by opening the helical conformation that forms the crystal lattice, thereby reducing the crystallinity of the PHA), while still being short enough to avoid problems with side chain recrystallization. The glass transition temperature (Tg) is also closely related to the segment mobility of the polymer chain, which determines the toughness and other physical properties of the material. It has been found that the Tg of PHAs is more effectively reduced by side chains of medium chain length. It has been further found that by using a variety of different hydroxyalkanoate monomers to form PHAs as random or nanodomain block copolymers, the molecular stereoregularity of the PHA polymer chain may be destroyed. This reduces the length of uniform segments along the polymer chain and therefore reduces molecular stereoregularity.

[0058] Therefore, in one aspect, the present disclosure provides a medium chain length polyhydroxyalkanoate (mcl-PHA) copolymer. Advantageously, the mcl-PHA copolymers of the present disclosure may have low crystallinity, low glass transition temperature and low shear modulus. These mcl-PHA copolymers can be obtained, for example, by randomizing a variety of hydroxyalkanoate monomers with medium side chain lengths using biosynthesis.

[0059] In one aspect, the mcl-PHA is a copolymer and is formed from at least three different types of hydroxyalkanoate monomers. As discussed herein, the inclusion of a plurality of different hydroxyalkanoate monomers in the mcl-PHA copolymers of the present disclosure helps disrupt the stereoregularity of the polymer backbone and prevents recrystallization of the mcl-PHA over time. Thus, in a particular aspect, the mcl-PHA is a copolymer comprising repeating units of at least three different hydroxyalkanoate monomers. Advantageously, the hydroxyalkanoate monomer is a medium chain hydroxyalkanoate and has, for example, C3-C 30In another instance, the copolymer comprises repeating units of at least four different hydroxyalkanoate monomers. In another instance, the copolymer comprises repeating units of at least 5 different hydroxyalkanoate monomers. In another instance, the copolymer comprises repeating units of at least 6 different hydroxyalkanoate monomers. In another instance, the copolymer comprises repeating units of at least 7 different hydroxyalkanoate monomers. In one instance, the copolymer comprises repeating units of three different hydroxyalkanoate monomers. In one instance, the copolymer comprises repeating units of four different hydroxyalkanoate monomers.

[0060] In one instance, each repeating unit of the mcl-PHA copolymer of the present disclosure is independently a repeating unit of formula (I):

[0061]

[0062] in:

[0063] R is C3-C 30 alkyl;

[0064] m is 0, 1, 2 or 3; and

[0065] n is an integer from 1 to 32.

[0066] In a particular embodiment, m is 1 and the copolymer is formed from 3-hydroxyalkanoate monomers.

[0067] When used herein, the term "alkyl" refers to a fully saturated straight or branched hydrocarbon. For illustrative purposes, which should not be construed as limiting the scope of the present invention, examples of alkyl include propyl, pentyl, hexyl, heptyl, nonyl, etc.

[0068] In a specific embodiment, R is C3-C 30 In one embodiment, R is C3-C 15 Alkyl, especially C3-C 15 In one embodiment, R is C3-C 13 Alkyl, especially C3-C 13 In one embodiment, R is C3-C 11 Alkyl, especially C3-C 11 In one embodiment, R is a C3-C9 alkyl group, in particular a C3-C9 straight chain alkyl group. In one embodiment, m is 1, and R is a C3-C9 alkyl group. 15 Alkyl or C3-C 13 Alkyl or C3-C 11 Alkyl or C3-C9 alkyl, especially C3-C 15 Straight chain alkyl or C3-C13 Straight chain alkyl or C3-C 11 Straight chain alkyl or C3-C9 straight chain alkyl.

[0069] In one embodiment, n is an integer from 1 to 24. In one embodiment, n is an integer from 1 to 16. In one embodiment, n is an integer from 1 to 3. In one embodiment, n is 1.

[0070] In one specific embodiment, m is 1, R is a C3 straight chain alkyl, and the hydroxyalkanoate monomer used to form the repeating unit is 3-hydroxyhexanoate. In one embodiment, m is 1, R is a C4 straight chain alkyl, and the hydroxyalkanoate monomer used to form the repeating unit is 3-hydroxyheptanoate. In one embodiment, m is 1, R is a C5 straight chain alkyl, and the hydroxyalkanoate monomer used to form the repeating unit is 3-hydroxyoctanoate. In one embodiment, m is 1, R is a C6 straight chain alkyl, and the hydroxyalkanoate monomer used to form the repeating unit is 3-hydroxynonanoate. In one embodiment, m is 1, R is a C7 straight chain alkyl, and the hydroxyalkanoate monomer used to form the repeating unit is 3-hydroxydecanoate. In one embodiment, m is 1, R is a C8 straight chain alkyl, and the hydroxyalkanoate monomer used to form the repeating unit is 3-hydroxyundecanoate. In one embodiment, m is 1, R is a C9 straight chain alkyl, and the hydroxyalkanoate monomer used to form the repeating unit is 3-hydroxydodecanoate. In one embodiment, m is 1, R is C 10 In one embodiment, m is 1, R is C 11 A straight chain alkyl group, and the hydroxyalkanoate monomer used to form the repeating unit is 3-hydroxytetradecanoate.

[0071] In one embodiment, the hydroxyalkanoate monomers used to form the mcl-PHA copolymers of the present disclosure are selected from 3-hydroxyhexanoate, 3-hydroxyheptanoate, 3-hydroxyoctanoate, 3-hydroxynonanoate, 3-hydroxydecanoate, 3-hydroxyundecanoate, 3-hydroxydodecanoate, 3-hydroxytridecanoate, 3-hydroxytetradecanoate, and combinations thereof. In one embodiment, the hydroxyalkanoate monomers used to form the mcl-PHA copolymers of the present disclosure are selected from 3-hydroxyhexanoate, 3-hydroxyoctanoate, 3-hydroxydecanoate, and 3-hydroxydodecanoate, and combinations thereof. In one embodiment, the hydroxyalkanoate monomers used to form the mcl-PHA copolymers of the present disclosure include 3-hydroxyhexanoate, 3-hydroxyoctanoate, 3-hydroxydecanoate, and 3-hydroxydodecanoate, and the copolymer is poly(3-hydroxyhexanoate-co-3-hydroxyoctanoate-co-3-hydroxydecanoate-co-3-hydroxydodecanoate).

[0072] In a specific embodiment, the mcl-PHA copolymer of the present disclosure is a nano-domain block copolymer. When used in this article, the term "nano-domain block copolymer" refers to a copolymer of repeating units comprising at least 2, more generally at least 3 or at least 4 different types of hydroxyalkanoate monomers, wherein each repeating unit independently comprises 1 to 32 continuous monomers of the same type. More generally, each repeating unit in the nano-domain block copolymer of the present disclosure independently comprises 2 to 32 or 16 to 32 or 24 to 32 continuous monomers of the same type. In one case, the block of each continuous monomer of the same type in the nano-domain block copolymer of the present disclosure is less than 20nm. It is not desired to be limited by any particular theory, and it is believed that tiny crystal units (i.e., blocks of nano-domain sizes) do not form stable crystals. Therefore, the nano-domain block copolymer is not troubled by the same recrystallization tendency as homopolymers or larger block copolymers.

[0073] It should be understood that the nano-domain block copolymers of the present disclosure may contain multiple different repeating units containing the same type of hydroxyalkanoate monomers in one copolymer. For example, the nano-domain block copolymer may contain: at least 1 (including 1, 2, 3, 4 or more) independently contains 1 to 32 consecutive repeating units of "A" type monomers (e.g., repeating units of Formula I); at least 1 (including 1, 2, 3, 4 or more) independently contains 1 to 32 consecutive repeating units of "B" type monomers (e.g., repeating units of Formula I); at least 1 (including 1, 2, 3, 4 or more) independently contains 1 to 32 consecutive repeating units of "C" type monomers (e.g., repeating units of Formula I); and at least 1 (including 1, 2, 3, 4 or more) independently contains 1 to 32 consecutive repeating units of "D" type monomers (e.g., repeating units of Formula I). ​​Repeating units containing monomers A, B, C or D may appear in any order.

[0074] In one embodiment, the mcl-PHA copolymer of the present disclosure is a random copolymer. When used herein, the term "random copolymer" refers to a copolymer comprising repeating units of at least 2, more typically at least 3 or at least 4 different types of hydroxyalkanoate monomers, wherein each repeating unit independently comprises 1 to 24 continuous monomers of the same type. More typically, each repeating unit in the random copolymer of the present disclosure independently comprises 1 to 16 or 1 to 10 or 1 to 3 continuous monomers of the same type. Typically, any continuous blocks of the same type of monomers present in the random copolymer of the present disclosure have nanodomain sizes. In one case, any continuous blocks of the same type of monomers in the random copolymer of the present disclosure are less than 20 nm. It should be understood that the random copolymer of the present disclosure may contain multiple different repeating units containing the same type of hydroxyalkanoate monomers in one copolymer. For example, the random copolymer may contain: at least 1 (including 1, 2, 3, 4 or more) independently containing 1 to 24 consecutive repeating units of "A" type monomers (e.g., repeating units of Formula I); at least 1 (including 1, 2, 3, 4 or more) independently containing 1 to 24 consecutive repeating units of "B" type monomers (e.g., repeating units of Formula I); at least 1 (including 1, 2, 3, 4 or more) independently containing 1 to 24 consecutive repeating units of "C" type monomers (e.g., repeating units of Formula I); and at least 1 (including 1, 2, 3, 4 or more) independently containing 1 to 24 consecutive repeating units of "D" type monomers (e.g., repeating units of Formula I). ​​The repeating units containing monomers A, B, C and D may appear in any order.

[0075] In another instance, the mcl-PHA copolymer of the present disclosure comprises 3-hydroxyhexanoate (e.g., repeating units comprising 3-hydroxyhexanoate), wherein the copolymer comprises from about 0.5 mol % to about 97 mol %, including from about 3 mol % to about 83 mol % or from about 17 mol % to about 50 mol % or from about 8 mol % to about 19 mol % 3-hydroxyhexanoate.

[0076] In another instance, the mcl-PHA copolymer of the present disclosure comprises 3-hydroxyheptanoate (e.g., repeating units comprising 3-hydroxyheptanoate), wherein the copolymer comprises from about 0.5 mol % to about 97 mol %, including from about 3 mol % to about 83 mol %, including from about 17 mol % to about 50 mol % or from about 23 mol % to about 86 mol % 3-hydroxyheptanoate.

[0077] In another instance, the mcl-PHA copolymer of the present disclosure comprises 3-hydroxyoctanoate (e.g., repeating units comprising 3-hydroxyoctanoate), wherein the copolymer comprises from about 0.5 mol % to about 97 mol %, including from about 3 mol % to about 83 mol % or from about 17 mol % to about 50 mol % or from about 32 mol % to about 65 mol % 3-hydroxyoctanoate.

[0078] In another instance, the mcl-PHA copolymer of the present disclosure comprises 3-hydroxynonanoic acid ester (e.g., repeating units comprising 3-hydroxynonanoic acid ester), wherein the copolymer comprises from about 0.5 mol % to about 97 mol %, including from about 3 mol % to about 83 mol % or from about 17 mol % to about 50 mol % or from about 7 mol % to about 67 mol % of 3-hydroxynonanoic acid ester.

[0079] In another instance, the mcl-PHA copolymer of the present disclosure comprises 3-hydroxydecanoate (e.g., repeating units comprising 3-hydroxydecanoate), wherein the copolymer comprises from about 0.5 mol % to about 97 mol %, including from about 3 mol % to about 83 mol % or from about 17 mol % to about 50 mol % or from about 20 mol % to about 40 mol % 3-hydroxydecanoate.

[0080] In another instance, the mcl-PHA copolymer of the present disclosure comprises 3-hydroxyundecanoate (e.g., repeating units comprising 3-hydroxyundecanoate), wherein the copolymer comprises from about 0.5 mol % to about 97 mol %, including from about 3 mol % to about 83 mol % or from about 17 mol % to about 50 mol % or from about 20 mol % to about 40 mol % of 3-hydroxyundecanoate.

[0081] In another instance, the mcl-PHA copolymer of the present disclosure comprises 3-hydroxydodecanoate (e.g., comprising repeating units of 3-hydroxydodecanoate), wherein the copolymer comprises from about 0.5 mol% to about 97 mol%, including from about 3 mol% to about 83 mol%, or from about 17 mol% to about 50 mol%, or from about 7 mol% to about 12 mol% of 3-hydroxydodecanoate. In one embodiment, the copolymer comprises at least 0.5 mol%, including at least 7 mol% and at least 10 mol% of 3-hydroxydodecanoate.

[0082] In another instance, the mcl-PHA copolymer of the present disclosure comprises 3-hydroxytridecanoate (e.g., repeating units comprising 3-hydroxytridecanoate), wherein the copolymer comprises from about 0.5 mol % to about 97 mol %, including from about 3 mol % to about 83 mol % or from about 17 mol % to about 50 mol % or from about 7 mol % to about 12 mol % of 3-hydroxytridecanoate.

[0083] In another instance, the mcl-PHA copolymer of the present disclosure comprises 3-hydroxytetradecanoate (e.g., repeating units comprising 3-hydroxytetradecanoate), wherein the copolymer comprises from about 0.5 mol % to about 97 mol %, including from about 3 mol % to about 83 mol % or from about 17 mol % to about 50 mol % or from about 7 mol % to about 12 mol % of 3-hydroxytetradecanoate.

[0084] In one embodiment, the mcl-PHA copolymer of the present disclosure has a major monomer content of 97 mol % or less, including 96 mol % or less or 83 mol % or less or 80 mol % or less or 50 mol % or less. In one embodiment, the mcl-PHA copolymer has a major monomer content of 50 mol % or less. When used herein, "major monomer" refers to the monomer present in the largest amount in the mcl-PHA copolymer. The term "minor monomer" refers to any monomer present in the mcl-PHA that is not a major monomer. For example, if the mcl-PHA copolymer contains 40 mol % of monomer A, 25 mol % of monomer B, 20 mol % of monomer C, and 15 mol % of monomer D, then monomer A is the major monomer and the mcl-PHA has a major monomer content of 40 mol %, while monomers B, C, and D are minor monomers.

[0085] In one embodiment, the mcl-PHA copolymers of the present disclosure have a secondary monomer content of at least 0.5 mol% for each secondary monomer, including at least 0.7 mol% or at least 1.0 mol% or at least 1.3 mol% or at least 1.5 mol% or at least 2 mol% or at least 2.8 mol% or at least 3 mol% or at least 4 mol% or at least 5.7 mol% or at least 10 mol% or at least 17 mol% for each secondary monomer. In one embodiment, the mcl-PHA copolymers of the present disclosure have a secondary monomer content of at least 10 mol% for each secondary monomer. In one embodiment, the mcl-PHA copolymers of the present disclosure comprise repeating units of two different hydroxyalkanoate monomers and have a secondary monomer content of at least 3 mol%, including at least 4 mol% or at least 17 mol%. In one embodiment, the mcl-PHA copolymers of the present disclosure comprise repeating units of three different hydroxyalkanoate monomers and have a secondary monomer content of at least 1.5 mol% or at least 2 mol% or at least 8.5 mol%. In one embodiment, the mcl-PHA copolymer of the present disclosure comprises repeating units of four different hydroxyalkanoate monomers and has a secondary monomer content of at least 1 mol %, or at least 1.3 mol %, or at least 5.7 mol %. In one embodiment, the mcl-PHA copolymer of the present disclosure comprises repeating units of seven different hydroxyalkanoate monomers and has a secondary monomer content of at least 0.5 mol %, or at least 0.7 mol %, or at least 2.8 mol %.

[0086] In one embodiment, the mcl-PHA copolymer of the present disclosure comprises about 350 to about 7000 hydroxyalkanoate monomers. In a specific embodiment, the mcl-PHA copolymer of the present disclosure has a number average molecular weight (Mn) of about 50,000 g / mole to about 1,000,000 g / mole, including about 50,000 g / mole to about 500,000 g / mole, including about 60,000 g / mole to about 200,000 g / mole, including about 79,000 g / mole to about 104,000 g / mole. In one instance, the mcl-PHA copolymers of the present disclosure have a weight average molecular weight (Mw) of about 100,000 g / mole to about 1,000,000 g / mole, including about 100,000 g / mole to about 500,000 g / mole, including about 125,000 g / mole to about 300,000 g / mole, including about 150,000 g / mole to about 218,000 g / mole. In one instance, the mcl-PHA copolymers of the present disclosure have a weight average molecular weight to number average molecular weight ratio (Mw / Mn) of 3 or less, including about 1.9 to about 2.2.

[0087] As discussed herein, the mcl-PHA copolymers of the present disclosure advantageously have properties that make them suitable for use as elastomers in chewing gum bases. In one instance, the mcl-PHA copolymers of the present disclosure have a glass transition temperature (Tg) of about 37°C or less, including about 10°C to about -57°C, or about -20°C to about -45°C, or about -30°C to about -57°C, or about -42°C to about -57°C. g ).

[0088] In one aspect, the mcl-PHA copolymers of the present disclosure have a crystalline melting point (T ) of about 65° C. or less, including about 37° C. or less, or including about 22° C. or less. m In one embodiment, the mcl-PHA copolymer of the present disclosure has a Tm of about 32°C to about 55°C or about 32°C to about 52°C. m It can be determined by differential scanning calorimetry (DSC).

[0089] In one instance, the mcl-PHA copolymers of the present disclosure have a crystallinity of about 25 wt % or less as determined by X-ray diffractometer (XRD). The weight percent crystallinity can be estimated from XRD using the following formula: Crystallinity (XRD) % = 100*Ac / (Ac+Aa), where Ac is the total area under the crystalline peak and Aa is the area under the amorphous halo.

[0090] In one instance, the crystal heat of fusion (ΔHm) is used as a measure of the relative amount of crystals in the mcl-PHA copolymer. In one instance, the mcl-PHA copolymers of the present disclosure have a ΔHm of about 35 J / g or less, including about 20 J / g or less, including about 10 J / g or less, including about 6 J / g to about 15 J / g, including about 6 J / g to about 12 J / g. In one embodiment, the ΔHm is 0 J / g. ΔHm can be measured using a differential scanning calorimeter (DSC).

[0091] In one embodiment, the mcl-PHA copolymer of the present disclosure has a molecular weight of about 1 x 10 3 dyn / cm 2 About 1x10 7 dyn / cm 2 (or 100Pa to 10 6 Pa), including about 2x10 4 dyn / cm 2 About 2x 10 5 dyn / cm 2 (or 2000 Pa to 20,000 Pa) of complex shear modulus (G*). The complex shear modulus can be measured using any suitable rotational rheometer.

[0092] In one embodiment, the mcl-PHA copolymer of the present disclosure has a molecular weight of about 1 x 10 4 Pa-s to about 7x 10 4 Complex viscosity (*η) in Pa-s.

[0093] In one aspect, the mcl-PHA copolymers of the present disclosure are produced using a modified version of a fermentation process commonly used to produce PHA polymers. For example, PHA polymers are commonly produced by standard fed-batch fermentation using bacterial cultures grown in bioreactors. After fermentation, the culture is harvested, for example by continuous flow centrifugation, the cell pellet is collected and the PHA polymer is extracted. A typical two-step fermentation process and details of cell harvest and PHA polymer extraction are described in Brandl et al., "Pseudomonas oleovorans as a Source of Poly(3-hydroxyalkanoates) for Potential Applications as Biodegradable Polyesters", Applied and Environmental Microbiology, (1988), 54: 1977-1982; and Elbahloul et al., "Large-Scale Production of Poly(3Hydroxyoctanoic Acid) by Pseudomonas putida GPo1 and a Simplified Downstream Process", Applied and Environmental Microbiology, (2009), 75: 643–651, which are incorporated herein by reference.

[0094] To produce the mcl-PHA copolymers of the present disclosure, a typical PHA polymer production process is modified by changing the feed solution used during fermentation to include certain fatty acids depending on the type of monomer to be included in the mcl-PHA copolymer. For example, mcl-PHA copolymers comprising repeating units of hydroxyhexanoate (e.g., 3-hydroxyhexanoate), hydroxyoctanoate (e.g., 3-hydroxyoctanoate), hydroxydecanoate (e.g., 3-hydroxydecanoate) and / or hydroxydodecanoate (e.g., 3-hydroxydodecanoate) can be produced by including C8 and C12 fatty acid substrates in the feed solution. mcl-PHA copolymers comprising repeating units of hydroxyheptanoate (e.g., 3-hydroxyheptanoate) and / or hydroxynonanoate (e.g., 3-hydroxynonanoate) can be produced by including C7 and C9 fatty acid substrates in the feed solution. mcl-PHA copolymers comprising repeating units of hydroxyundecanoate (e.g., 3-hydroxyundecanoate) can be produced by including a C11 fatty acid substrate in the feed solution. The mcl-PHA copolymers comprising repeating units of hydroxy tridecanoate (e.g., 3-hydroxy tridecanoate) can be produced by including a C13 fatty acid substrate in the feed solution. The mcl-PHA copolymers comprising repeating units of hydroxy tetradecanoate (e.g., 3-hydroxy tetradecanoate) can be produced by including a C14 fatty acid substrate in the feed solution. It should be understood that the fatty acid substrate contained in the feed solution can be changed according to the desired composition of the mcl-PHA copolymer. In one embodiment, the feed solution comprises a mixture of octanoate (e.g., sodium octanoate or ammonium octanoate) and dodecanoate (e.g., sodium dodecanoate or ammonium dodecanoate). The feed solution may include additional inorganic salts, including but not limited to NH4Cl, KH2PO4, MgSO4, and combinations thereof.

[0095] Bacteria suitable for producing the mcl-PHA copolymers of the present disclosure include Pseudomonas putida (e.g., Pseudomonas putida BM01, Pseudomonas putida KT2442 (DSM26250, 26251, 26252, or 26253), Pseudomonas putida KT2440 (ATCC47054; DSM6125 of DSMZ), Pseudomonas putida HKT554 (National Institute of Advanced Industrial Science and Technology, FERM P-21149), Pseudomonas putida GPo1), Pseudomonas aeruginosa, and Pseudomonas delafieldii. In one embodiment, the bacterium is a non-genetically modified (GMO) bacterial strain. The cultures may be grown in any suitable medium, such as a mineral salts medium.

[0096] Chewing Gum Base

[0097] In another aspect, the present disclosure relates to a chewing gum base comprising the mcl-PHA copolymer of the present disclosure. In one instance, the chewing gum base comprises at least 20 wt %, including in an amount of about 40 wt % to about 70 wt % of the chewing gum base of the mcl-PHA copolymer.

[0098] Elastomers provide rubber-like cohesive properties for chewing gum, and the cohesive properties change with the chemical structure of this composition and its composite mode with other compositions. However, many traditional elastomers are petroleum-based. It has been found that mcl-PHA copolymers of the present disclosure can be used as part or even complete substitutes for conventional petroleum-based elastomers in chewing gum base. Petroleum-based elastomer ingredients include, for example, conventional petroleum-based elastomers such as isobutylene-isoprene copolymers (butyl rubber), polyisobutylene (e.g., low or medium molecular weight), butadiene-styrene copolymers (SBR), vinyl polymer elastomers (polyvinyl acetate, polyethylene, vinyl acetate / vinyl laurate, vinyl acetate / vinyl stearate, ethylene / vinyl acetate) and polybutadiene.

[0099] Thus, in one instance, the chewing gum base of the present disclosure comprises 30 wt% or less, preferably 15 wt% or less, preferably 10 wt% or less of petroleum-based polymers (including elastomers and polyterpene resins). In a specific embodiment, the chewing gum base of the present disclosure is substantially free (i.e., contains 5 wt% or less, including 2 wt% or less or 1 wt% or less or 0.5 wt% or less) or free (i.e., contains 0 wt%) of such petroleum-based ingredients.

[0100] In addition, conventional gum base elastomers have long straight chains and flexible polymer chains, and are easily entangled. This high entanglement density of high molecular weight rubber produces high cohesion, which is usually too cohesive so that people cannot get comfortable chewing. Therefore, usually in gum base formula, some miscible or partially miscible low molecular weight components such as polyterpenes and rosin esters are added as tackifiers to reduce the cohesion of rubber. The weight ratio of resin / rubber is generally about 1.5 to 4.5. The rosin ester commonly referred to as ester glue comprises the glyceride of partially hydrogenated rosin, the glyceride of polymerized rosin, the glyceride of partially or completely dimerized rosin, the glyceride of rosin, the pentaerythritol ester of partially hydrogenated rosin, the methyl ester of rosin and the partially hydrogenated methyl ester, the pentaerythritol ester of rosin, the glyceride of wood rosin, the glyceride of gum rosin, the synthetic such as derived from the terpene resin of α-pinene, β-pinene and / or d-limonene, and any suitable combination of above-mentioned substances.

[0101] Advantageously, the mcl-PHA copolymers of the present disclosure are highly branched, with medium-length side chains along the polymer backbone. The presence of the medium-length side chains acts as internal spacers to reduce entanglement of the polymer backbone. Therefore, gum bases containing the mcl-PHA copolymers of the present disclosure do not require the levels of viscosity enhancers (e.g., resins) that are typically present in gum bases in order to soften the texture.

[0102] Thus, in another instance, the chewing gum base of the present disclosure further comprises a tackifier, including a natural or bio-based (i.e., non-petroleum-based) resin such as rosin or rosin ester, in an amount of about 10 wt % or less, including about 5 wt % or less or about 2 wt % or less. In one embodiment, the chewing gum base of the present disclosure is free of (i.e., comprises 0 wt %) such a tackifier.

[0103] In addition to the mcl-PHA copolymer, the chewing gum base of the present disclosure may also contain additional non-petroleum-based ingredients, including but not limited to inorganic fillers, fats, emulsifiers, natural waxes, antioxidants and combinations thereof. Such additional non-petroleum-based ingredients may be included in the chewing gum base in an amount of at least 1% by weight.

[0104] Gum base of the present disclosure can also comprise non-petroleum-based plasticizer, is used to change the firmness of gum base.The plasticizer used in gum base of the present disclosure can comprise triacetin, medium-chain triglyceride, monoglyceride, diester and triester of fatty acid, non-hydrogenated, partially hydrogenated and fully hydrogenated cottonseed oil, soybean oil, palm oil, palm kernel oil, coconut oil, safflower oil, tallow, cocoa butter, triglyceride of unsaturated oils containing carbon chain length as one or more constituent groups of fatty acid of 6 to 18, monoglyceride, diglyceride, acetylated monoglyceride, diglyceride and lecithin of distillation may contain the triglyceride level lower than 2 weight % coming from their manufacturing process.Monoglyceride and diglyceride can be considered to belong to the same family with fat.In one embodiment, described plasticizer is selected from triacetin, acetylated monoglyceride, diester and triester of short-chain fatty acid, acetylated monoglyceride, diester and triester of medium-chain fatty acid, acetylated monoglyceride and combination thereof of long-chain fatty acid.

[0105] The plasticizer used can be a type or a combination that exceeds a type.Usually, the ratio of one to another depends on the corresponding softening point of each, the impact of each on the flavoring agent release and the corresponding viscosity degree that each causes to the chewing gum.Plasticizer can be included with the level of about 1 % by weight to about 50 % by weight or about 3 % by weight to about 40 % by weight or about 5 % by weight to about 35 % by weight of gum base.

[0106] The non-petroleum based emulsifiers used in the gum base of the present disclosure, which sometimes also have plasticizing properties, can be selected from the group consisting of glyceryl mono- and distearate, lecithin, mono- and di-glycerides of fatty acids, triacetin, acetylated monoglycerides, polyglycerol esters, triacetin and sugar polyesters, and combinations thereof.

[0107] The gum base can also include fillers or texturizers. Fillers / texturizers are inorganic water-insoluble powders normally, such as magnesium carbonate and calcium carbonate, crushed limestone, silicate types such as magnesium silicate and aluminum silicate, clay, aluminum oxide, talc, titanium oxide, monocalcium phosphate, dicalcium and tricalcium and calcium sulfate. Insoluble organic fillers include cellulose polymers such as wood, and any combination of these materials can also be used. In one embodiment, the gum base comprises 1 % by weight to 50 % by weight, more generally 15 % by weight to 40 % by weight of filler.

[0108] The gum base of the present disclosure may also contain natural wax or may be substantially free of wax. The example of a wax-free gum base is disclosed in U.S. Patent No. 5,286,500, which is incorporated herein by reference. Wax helps the solidification of the gum base and improves shelf life and texture. In one embodiment, the chewing gum base does not contain paraffin wax.

[0109] Other optional ingredients such as antioxidants can also be used in gum base. Antioxidants extend the shelf life and storage of gum base, finished chewing gum or their corresponding components including fat and flavoring oil. Antioxidants suitable for use in gum base or chewing gum of the present disclosure include butylated hydroxyanisole (BHA), butylated hydroxytoluene (BHT), beta-carotene, tocopherol, acidulant such as vitamin C, propyl gallate and other synthetic and natural antioxidants or their combination. Preferably, the antioxidant used in gum base is butylated hydroxyanisole (BHA), butylated hydroxytoluene (BHA), tocopherol or its combination.

[0110] Flavorings and coloring agents impart properties or remove or mask undesirable properties. Coloring agents can typically include FD&C type lakes, plant extracts, fruit and vegetable extracts, and titanium dioxide. Flavoring agents can typically include cocoa powder, heat-modified amino acids, and other vegetable extracts.

[0111] In certain embodiments, the chewing gum base may optionally include a natural elastomer. Natural elastomers include jelutong, lechi caspi, perillo, soma, bidentate galanthus, chocolate galanthus, nispero, rosindinha, chicle, gutta hang kang, hevea, TKS, guayule and combinations thereof. Natural elastomers may be present in the gum base at a level of about 1% by weight to about 30% by weight, or about 2% by weight to about 25% by weight, or about 5% by weight to about 20% by weight of the gum base. Alternatively, the chewing gum base may be free of natural elastomers (i.e., comprising 0% by weight).

[0112] The selection of the various components in the chewing gum base or chewing gum formulation of the present disclosure is generally determined by a variety of factors, including, for example, desired properties (e.g., physical properties (mouth feel), taste, smell, etc.) and / or applicable regulatory requirements (e.g., in order to obtain a food grade product, food grade components such as food grade approved oils such as vegetable oils may be used).

[0113] The chewing gum base of the present disclosure can be formulated to have good or even outstanding chewing properties. Good or outstanding chewing properties mean that the cud is neither too soft nor too cohesive, neither too elastic nor too rigid, does not make noise or creak, is smooth but not too slippery, and therefore consumers are happy to chew. The individual preferences of each consumer are different in these properties. Formulators of ordinary skill in the art will be able to formulate a gum base that satisfies the target consumer within the limitations of the present disclosure.

[0114] The disclosed gum base can be produced using conventional mixing techniques, including conventional batch mixing techniques. Specifically, the mcl-PHA can be transferred to a batch mixer for compounding. Any standard commercially available mixer (e.g., a bow knife mixer) can be used for this purpose. Compounding generally includes merging the mcl-PHA with a filler and any plasticizer, and mixing until a homogeneous mixture is produced, which generally lasts from about 30 to about 70 minutes, or a shorter time in certain embodiments. Thereafter, any desired additional fillers and plasticizers are added, followed by an emulsifier, while mixing to homogeneity after each addition. Minor ingredients, such as antioxidants and colorants, can be added at any time in the process.

[0115] Continuous processes using mixing extruders known in the art can also be used to prepare the gum base. In a typical continuous mixing process, the initial ingredients including mcl-PHA are continuously metered into the extruder port at various points along the length of the extruder corresponding to a batch processing sequence.

[0116] After the initial ingredients are mixed and fully compounded, the remaining gum base ingredients are metered into the port or injected at various different points along the length of the extruder. Usually, any remaining mcl-PHA components or other components are added after the initial compounding stage. The composition is then further processed to produce a uniform mass and then discharged from the extruder outlet. Usually, the transit time through the extruder is less than 1 hour.

[0117] Exemplary methods of continuous mixing include the following, each of which is incorporated herein by reference in its entirety to the extent not inconsistent with the teachings herein: (i) U.S. Patent No. 6,238,710, which describes a method for continuously manufacturing chewing gum base requiring compounding of all ingredients in a single extruder; (ii) U.S. Patent No. 5,419,919, which discloses the use of a paddle mixer to continuously manufacture gum base by selectively feeding different ingredients at different locations in the mixer; and (iii) U.S. Patent No. 5,397,580, which discloses continuous gum base manufacturing in which two continuous mixers are arranged in series and the blend from the first continuous mixer is continuously added to the second extruder.

[0118] The finished gum base can be extruded or cast into any desired shape (e.g., balls, pellets, sheets or plates) and allowed to cool and solidify. In some cases, it may be preferred to use an underwater granulation process for this purpose.

[0119] Chewing Gum Recipe

[0120] The chewing gum base of the present disclosure can be used to form chewing gum. The chewing gum base of the present disclosure can account for about 5 weight % to about 95 weight % of the chewing gum. More generally, the chewing gum base can account for about 10 weight % to about 50 weight % of the chewing gum or about 20 weight % to about 35 weight % of the chewing gum.

[0121] In addition to the water-insoluble gum base portion, a typical chewing gum composition also includes a water-soluble bulk portion (or bulking agent) and one or more flavoring agents. The water-soluble portion may include water-soluble softeners, bulking agents or bulk sweeteners, binders, high-intensity sweeteners, flavoring agents (which may be water-insoluble), colorants, chewing gum emulsifiers, acidulants, fillers, antioxidants, and other components that provide desired attributes.

[0122] Water-soluble softeners, which may also be referred to as water-soluble plasticizers and plasticizers, typically comprise between about 0.5% by weight and about 25% by weight of the chewing gum. Water-soluble softeners may include glycerin, lecithin, and combinations thereof. Aqueous sweetener solutions, such as aqueous solutions containing sorbitol, hydrogenated starch hydrolysate (HSH), corn syrup, and combinations thereof, may also be used as softeners and binders in chewing gum.

[0123] Bulking agent or bulk sweetener can be used for providing sweet taste, volume and texture for product in chewing gum of the present disclosure.Typical bulking agent comprises sugar, sugar alcohol and combination thereof.Bulking agent accounts for about 5 wt % to about 95 wt % of described chewing gum usually, is more generally about 20 wt % to about 80 wt %, is more generally about 30 wt % to about 70 wt % of described chewing gum.Carbohydrate bulking agent generally comprises sugary component known in chewing gum field, includes but not limited to sucrose, dextrose, maltose, dextrin, dry invert sugar, fructose, levulose, galactose, corn syrup solids etc. separately or in combination.In sugar-free chewing gum, sugar bulking agent is replaced with sugar alcohol such as sorbitol, maltitol, erythritol, isomalt, mannitol, xylitol, isomaltulose, hydrogenated starch hydrolysate, psicose and combination thereof.Sugar alcohol is sometimes referred to as polyol or alditol.Also can use the combination of sugar and sugar-free bulking agent.

[0124] In addition to the above-mentioned bulk sweeteners, chewing gum also generally includes a binder / softener in the form of a high solid solution of syrup or sugar and / or sugar alcohol. In the case of sugar-containing chewing gum, corn syrup and other dextrose syrups (which contain dextrose and a significant amount of higher sugars) are most commonly used. These syrups include syrups of various different DE levels, including high maltose syrups and high fructose syrups. In the case of sugar-free products, sugar alcohol solutions are generally used, including sorbitol solutions and hydrogenated starch hydrolysate syrups. Also useful are those syrups disclosed in, for example, US 5,651,936 and US2004 / 234648, which are incorporated herein by reference. Such syrups are used to soften the initial chewing of the product, reduce fragility and brittleness, and improve flexibility in stick-shaped and sheet-shaped products. They can also control the increase or loss of moisture, and provide a certain degree of sweetness according to the specific syrup used. In the case of syrups and other aqueous solutions, it is generally desirable to use the lowest practical level of water in the solution, the minimum level required to keep the solution free-flowing at acceptable operating temperatures. The use level of such syrups and solutions should be adjusted to limit the total moisture in the chewing gum to less than 3 weight percent, preferably less than 2 weight percent, and most preferably less than 1 weight percent.

[0125] High-intensity artificial sweeteners can also be used in combination with the above-mentioned sweeteners. Preferred sweeteners include, but are not limited to, sucralose, aspartame, salts of acesulfame potassium, alitame, neotame, saccharin and its salts, cyclamic acid and its salts, glycyrrhizin, stevia and stevia compounds such as rebaudioside (e.g., rebaudioside A or rebaudioside M), dihydrochalcone, thaumatin, tamarind, monk fruit, etc., alone or in combination. In order to provide a more lasting sweetness and flavor sensation, it may be necessary to encapsulate or otherwise control the release of at least a portion of the artificial sweetener. Technologies such as wet granulation, wax granulation, spray drying, spray chilling, fluidized bed coating, coagulation, and fiber extrusion can be used to achieve the desired release characteristics.

[0126] The use level of the artificial sweetener varies greatly and depends on factors such as the potency of the sweetener, the rate of release, the desired sweetness of the product, the level and type of flavoring used, and cost considerations. Thus, the active level of the artificial sweetener may vary from 0.02% by weight to about 8% by weight. When a carrier for encapsulation is included, the use level of the encapsulated sweetener will be proportionally increased.

[0127] Combinations of sugar and / or sugar-free sweeteners can be used in chewing gum. In addition, the softener may also provide additional sweetness, such as when using sugar or sugar alcohol aqueous solutions.

[0128] If low-calorie chewing gum is needed, low-calorie bulking agents can be used. Examples of low-calorie bulking agents include: polydextrose; oligofructose (Raftilose), Raftilin; oligofructose (NutraFlora); oligomeric palatinose; guar gum hydrolysate (Sun Fiber); erythritol or indigestible dextrin (Fibersol). However, other low-calorie bulking agents can be used. In addition, the caloric content of chewing gum can be reduced by increasing the relative level of gum base while reducing the level of caloric sweeteners in the product. This can be done with or without a reduction in the weight of the single piece.

[0129] Flavoring agents and coloring agents impart characteristics or remove or mask undesirable characteristics. Various flavoring agents can be used. Flavoring agents can be used in an amount of 0.1% by weight to about 15% by weight, preferably about 0.2% by weight to about 5% by weight of the chewing gum. Flavoring agents can include essential oils, synthetic flavoring agents or mixtures thereof, including but not limited to oils such as citrus oils, fruit essences, peppermint oil, spearmint oil, other peppermint oils, clove oil, wintergreen oil, anise oil, etc. derived from plants and fruits. Artificial flavoring agents and components can also be used. Natural and artificial flavoring agents can be combined in any sensory acceptable manner. It can also be included in a sensitizer component that imparts a tingling sensation or thermal response such as cooling or heating effects when chewing. Such components include cyclic and non-cyclic carboxamides, menthol derivatives and capsaicin, etc. Acidulants can be included to impart sour taste.

[0130] The chewing gum composition made using the chewing gum base of the present disclosure may also have spray-dried flavorings as a partial or complete substitute for liquid flavorings. The loading of the spray-dried flavorings used in the present invention can be about 20% of active substances. The use amount of the spray-dried flavorings can be up to about 2% by weight of the chewing gum composition. In certain embodiments, the spray-dried flavorings are used in an amount ranging from about 0.2% by weight to about 2% by weight of the chewing gum composition. Even more preferably, the spray-dried flavorings are used in about 1% by weight of the chewing gum composition.

[0131] Optional ingredients such as colorants, emulsifiers and medicaments, cooling agents, oral sensitizers, active agents (e.g., caffeine, nicotine, etc.), antimicrobial agents, tooth whitening agents, drugs, breath fresheners, health care agents, slimming agents, and combinations thereof, can be added to chewing gum. Colorants can typically include FD&C type lakes, plant extracts, fruit and vegetable extracts, and titanium dioxide. The chewing gum of the present disclosure can also include optional ingredients, such as dental health active substances such as minerals, nutritional supplements such as vitamins, health-promoting active substances such as antioxidants such as resveratrol, medicinal compounds, and other such additives. These active agents can be added neat to the chewing gum mass or encapsulated using known means to extend release and / or prevent degradation. The active agent can be added to existing coatings, rolling compounds, and liquid or powder fillings.

[0132] The gum base of the present disclosure may be included in a chewing gum formulation. Generally, chewing gum is manufactured by sequentially adding various chewing gum ingredients to a commercially available mixer known in the art. After the initial ingredients have been thoroughly mixed, the chewing gum mass is discharged from the mixer and formed into a desired shape, such as by rolling into sheets and cutting into sticks, extruding into blocks or casting into pellets.

[0133] Typically, the ingredients are mixed by first melting the gum base and adding it to the running mixer. The gum base can also be melted in the mixer itself. Coloring agents or emulsifiers can also be added at this time. Softeners such as glycerine can also be added at this time with syrup and a portion of bulking agent / sweetener. The bulking agent / sweetener of another portion can then be added to the mixer. Flavorings are usually added with the last portion of bulking agent / sweetener. High intensity sweeteners are preferably added after adding the last portion of bulking agent and flavorings.

[0134] The entire mixing procedure usually takes 5 to 15 minutes, and sometimes longer mixing times may be required. Those skilled in the art will recognize that many variations of the above procedure can be followed. A specifically envisioned embodiment is to use an extrusion mixer for continuous processing. In such a process, ingredients are continuously added at various points along the length of the extruder, while uniformly mixed chewing gum is continuously discharged from the discharge end of the extruder. U.S. Patent No. 6,017,565, incorporated herein by reference, discloses a continuous manufacturing process that automatically and continuously feeds ingredients into the equipment, mixes and discharges the desired final product. The final product is automatically dusted, rolled, scored and packaged. U.S. Patent No. 5,543,160 discloses a manufacturing process using efficient continuous mixing that does not require separate gum base manufacturing.

[0135] After mixing, the chewing gum is formed into the final product shape using known techniques, which may be extrusion, rolling, sheeting, scoring or molding. The final product shape may be a stick, sheet, block, pellet, ball or any other desired shape.

[0136] Pellets and spherical forms are usually pan-coated. Traditional pan-coating procedures are usually coated with sucrose or other saccharide materials that can replace sucrose. Some of these components include but are not limited to erythritol, sorbitol, dextrose, maltose, xylitol, maltitol, hydrogenated isomaltulose and other new polyols or combinations thereof. These materials can be blended with pan-coating modifiers, which include but are not limited to gum arabic, maltodextrin, corn syrup, gelatin, cellulose materials such as carboxymethyl cellulose or hydroxymethyl cellulose, starch and modified starch, plant gums such as alginate, locust bean gum, guar gum and tragacanth gum, insoluble carbonates such as calcium carbonate or magnesium carbonate and talc. Erythritol can also be used as a pan-coating modifier with other pan-coating materials to improve product quality. Anti-adhesive agents can also be added as pan-coating modifiers, which allow the use of a variety of different sugars and sugar alcohols to develop new pan-coating or coated chewing gum products. Flavorings may also be added along with erythritol sweetener to create a unique product profile.

[0137] If the chewing gum composition is in the form of a pellet, the initial coating syrup should have a higher level of binder in the pre-coating, such as gum arabic or tara gum, because traditional pre-coatings do not adhere to the pellets as they do on traditional chewing gum compositions. The increase in binder allows for proper adhesion of the pre-coating. The present invention can be coated in an amount ranging from about 30% to about 38%. Preferably, the coating is present at about 32% to about 36%.

[0138] Example

[0139] Example 1: Preparation of mcl-PHA copolymer

[0140] In this example, poly (3-hydroxyhexanoate-co-3-hydroxyoctanoate-co-3-hydroxydecanoate-co-3-hydroxydodecanoate) mcl-PHA copolymer (FBF-4) was prepared using a standard two-step fed batch fermentation process. The mcl-PHA copolymers produced in this example all contained 32 mol%-65 mol% of 3-hydroxyoctanoate, 20 mol%-40 mol% of 3-hydroxydecanoate, 9 mol%-19 mol% of 3-hydroxyhexanoate, and 7 mol%-12 mol% of 3-hydroxydodecanoate.

[0141] The mcl-PHA copolymer was produced from a culture of Pseudomonas putida GPo1 (ATCC 29347) using a standard two-step fed-batch fermentation process modified to include a mixture of sodium octanoate and sodium dodecanoate in the feed solution. After fermentation, the cells were harvested by continuous flow centrifugation and the mcl-PHA copolymer was extracted using standard techniques. Details of the two-step fermentation process as well as cell harvesting and PHA polymer extraction are described in Brandl et al., "Pseudomonas oleovorans as a Source of Poly(3-hydroxyalkanoates) for Potential Applications as Biodegradable Polyesters", Applied and Environmental Microbiology, (1988), 54: 1977-1982; and Elbahloul et al., "Large-Scale Production of Poly(3Hydroxyoctanoic Acid) by Pseudomonas putida GPo1 and a Simplified Downstream Process", Applied and Environmental Microbiology, (2009), 75: 643-651.

[0142] A high cell density was obtained (15.8 g / L dry cell weight). The mcl-PHA content in the cells reached 58.4 wt%.

[0143] Various properties of the mcl-PHA copolymer are described in Table 1:

[0144] Table 1: mcl-PHA properties

[0145]

[0146] 1 ΔHm was measured using Discovery Differential Scanning Calorimetry (DSC) (TA Instrument) using the following setup: Sample Pan and Cover - T zero Pot and sealing cover; heating rate - 10°C / min; cycle - heating - cooling - heating; temperature range - 85°C to 150°C.

[0147] The complex shear modulus of FBF-4 was measured using an ARES G2 rotational rheometer (TA Instruments) while heating from 20°C to 80°C (1.3-1.5 mm x φ8 mm PP; frequency = 10 rad / s; heating rate = 3.0°C / min). The results were compared with those of butyl rubber and a commercially available gum base (Comparative Example 1). The results are described in Figure 1 As can be seen from Figure 1 As can be seen, amorphous mcl-PHA copolymer is softer than butyl rubber, while slightly crystalline mcl-PHA is harder than butyl rubber. The mcl-PHA copolymer behaves in a manner similar to the commercially available gum base.

[0148] Example 2-6: Gum Base

[0149] In this example, gum bases containing mcl-PHA (FBF-4) of Example 1 were prepared (Examples 2-6) and compared with three commercial gum bases (Comparative Examples 1-3). The formulations of the gum bases of the present invention and the comparative gum bases are described in Table 2:

[0150] Table 2: Gum base formula

[0151]

[0152]

[0153] The formulations of Examples 2-6 containing the mcl-PHA copolymer of Example 1 were prepared in a batch mixer with a rotary cutter (Haake Polylab System, Thermo Electron Co.) at 120° C. and 35 rpm following the mixing procedure set forth in Table 3:

[0154] Table 3: Mixing Procedure for Gum Bases of Examples 2-6

[0155]

[0156] The complex viscosity of the gum base containing mcl-PHA of Example 2 was compared with three commercially available gum bases (Comparative Examples 1-3) that did not contain mcl-PHA. The results are described in Figure 2 middle.

[0157] As can be seen from these results, chewing gum bases prepared using the mcl-PHA copolymers of the present disclosure have rheological properties comparable to commercially available gum bases. Advantageously, the mcl-PHA copolymers of the present disclosure can be used to prepare chewing gum bases having suitable rheological properties without the need to include petroleum-based polymers such as butyl rubber, polyisobutylene and / or polyvinyl acetate or resins such as rosin esters. Therefore, the mcl-PHA copolymers of the present disclosure can be used as a complete or partial replacement for conventional elastomers and resins.

[0158] Example 7: Chewing Gum Formulation

[0159] In this example, a chewing gum containing the mcl-PHA copolymer of the present disclosure was prepared.

[0160] The gum base prepared in the previous example was mixed with xylitol, sorbitol and filler in a bow knife mixer at 55°C for 8-10 minutes, and then the flavoring, sensate and high intensity sweetener were added to the mixer and mixed for 4-6 minutes. The chewing gum mass was taken out of the mixer for rolling and scoring. The gum base formula is described in the following table:

[0161] Table 4: Chewing gum formula

[0162]

[0163] Comparative Example A: Rheological Properties of PHA Homopolymer

[0164] In this comparative example, chewing gum was formed from a gum base containing a PHA homopolymer of polyhydroxycaprylate and subjected to rheology testing.

[0165] A comparative chewing gum base was prepared using standard techniques according to the following formulation:

[0166] Table 5: Comparative Gum Base A

[0167] Element quantity(%) Antioxidants 0.05 Glyceryl Monostearate 7.45 Polyhydroxycaprylate 35 Rosin ester 10 Triacetin 6 wax 6.5 Crushed limestone 35

[0168] The chewing gum base containing polyhydroxycaprylate was formulated into chewing gum according to the following formula using standard techniques:

[0169] Table 6: Comparative chewing gum A

[0170] Element quantity(%) Gum Base A 35 Corn syrup 15 Powdered sugar 47.75 Glycerides 1.5 Flavoring 0.75

[0171] 5 g of comparative chewing gum A was extracted with tap water overnight. The chewing gum was manually kneaded in a 50°C water bath for 2 minutes and then wiped dry with a paper towel. Some samples of the resulting cuds were then subjected to rheological property analysis, and other samples of the chewing gum cuds were sealed in moisture barrier bags (HBO) and stored at room temperature (20-22°C) for 24 hours before being subjected to rheological analysis. The rheological properties of the chewing gum cuds were analyzed as follows: a sample of the chewing gum cud was placed in a 37°C water bath for 15 minutes and then measured by a double cycle punch test using a texture analyzer (Stevens Mechtric). The results are shown in Figure 3 middle.

[0172] As can be seen from Figure 3 As can be seen, just after forming (i.e., before storage), the rheological properties of the cud were within the normal range for a chewing gum cud. However, after 24 hours of storage, the cud exhibited rheological properties that were well outside the normal range and were not suitable for a chewing gum cud. These results confirm that recrystallization of the PHA homopolymer over time results in undesirable rheological properties for chewing gum.

[0173] This written description uses examples to disclose the invention, including the best mode thereof, to enable any person skilled in the art to practice the invention, including making and using any devices or systems and performing any incorporated methods. The patentable scope of the invention is defined by the claims, and may include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if they have structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal language of the claims.

Claims

1. A chewing gum base comprising a medium chain length polyhydroxyalkanoate copolymer comprising repeating units of at least four different hydroxyalkanoate monomers, wherein each repeating unit is independently a repeating unit of formula (I): in: R is C3-C 30 alkyl; m is 0, 1, 2, or 3; and n is an integer from 1 to 32, wherein the copolymer is a random copolymer, and wherein the copolymer has a crystallinity of 25 wt% or less.

2. The chewing gum base according to claim 1, wherein the copolymer comprises repeating units of four different hydroxyalkanoate monomers.

3. The chewing gum base according to claim 1, wherein m is 1.

4. The chewing gum base according to claim 1, wherein R is C3-C 15 alkyl.

5. The chewing gum base according to claim 4, wherein R is C3-C 11 alkyl.

6. The chewing gum base according to claim 4, wherein R is a C3-C9 alkyl group.

7. The chewing gum base according to claim 1, wherein n is an integer from 1 to 24.

8. The chewing gum base according to claim 7, wherein n is an integer from 1 to 16.

9. The chewing gum base according to claim 8, wherein n is an integer from 1 to 3.

10. The chewing gum base according to claim 1, wherein the hydroxyalkanoate monomer is selected from the group consisting of 3-hydroxyhexanoate, 3-hydroxyheptanoate, 3-hydroxyoctanoate, 3-hydroxynonanoate, 3-hydroxydecanoate, 3-hydroxyundecanoate, 3-hydroxydodecanoate, 3-hydroxytridecanoate, 3-hydroxytetradecanoate, and combinations thereof.

11. The chewing gum base of claim 10, wherein the hydroxyalkanoate monomers include 3-hydroxyhexanoate, 3-hydroxyoctanoate, 3-hydroxydecanoate, and 3-hydroxydodecanoate.

12. Chewing gum base according to claim 10 or 11, wherein the copolymer comprises 8 to 19 mol% of 3-hydroxyhexanoate.

13. The chewing gum base of claim 10, wherein the copolymer comprises 32 mol% to 65 mol% of 3-hydroxyoctanoate.

14. The chewing gum base of claim 10, wherein the copolymer comprises 20 mol% to 40 mol% of 3-hydroxydecanoate.

15. The chewing gum base of claim 10, wherein the copolymer comprises at least 0.5 mole % of 3-hydroxydodecanoate.

16. The chewing gum base according to claim 15, wherein the copolymer comprises at least 7 mol% of 3-hydroxydodecanoic acid ester.

17. The chewing gum base according to claim 16, wherein the copolymer comprises at least 10 mol% of 3-hydroxydodecanoate.

18. The chewing gum base of claim 16, wherein the copolymer comprises 7 to 12 mol% of 3-hydroxydodecanoic acid ester.

19. The chewing gum base of claim 1, wherein the copolymer comprises blocks of nano-domain size.

20. The chewing gum base of claim 1, wherein the copolymer comprises 350 to 7000 monomers.

21. The chewing gum base of claim 1, wherein the copolymer has a major monomer content of 97 mol% or less.

22. The chewing gum base according to claim 21, wherein the copolymer has a main monomer content of 50 mol% or less.

23. The chewing gum base of claim 1, wherein the copolymer has a secondary monomer content of at least 0.5 mole % for each secondary monomer.

24. The chewing gum base of claim 23, wherein the copolymer has a secondary monomer content of at least 10 mole % for each secondary monomer.

25. The chewing gum base of claim 1, wherein the copolymer has a glass transition temperature (T g ).

26. The chewing gum base according to claim 25, wherein the copolymer has a glass transition temperature (Tg) of -20°C to -45°C. g ).

27. The chewing gum base of claim 1, wherein the copolymer has a crystalline melting point (T m ).

28. The chewing gum base according to claim 27, wherein the copolymer has a crystalline melting point (T m ).

29. The chewing gum base of claim 1, wherein the copolymer has a crystalline heat of fusion (ΔHm) of 35 J / g or less.

30. The chewing gum base according to claim 29, wherein the copolymer has a crystalline heat of fusion (ΔHm) of 20 J / g or less.

31. The chewing gum base according to claim 1, wherein the copolymer has a viscosity of 1×10 3 dyn / cm 2 Up to 1×10 7 dyn / cm 2 Complex shear modulus (G*).

32. The chewing gum base of claim 31, wherein the copolymer has a 4 dyn / cm 2 Up to 2×10 5 dyn / cm 2 The complex shear modulus (G * ).

33. The chewing gum base of claim 1, wherein the copolymer has a number average molecular weight of 50,000 to 1,000,000 g / mole.

34. The chewing gum base of claim 33, wherein the copolymer has a number average molecular weight of 79,000 to 104,000 g / mole.

35. The chewing gum base of claim 1, wherein the copolymer has a weight average molecular weight of 100,000 to 1,000,000 g / mole.

36. The chewing gum base of claim 35, wherein the copolymer has a weight average molecular weight of 150,000 to 218,000 g / mole.

37. The chewing gum base according to claim 1, wherein the copolymer has a viscosity of 1×10 4 Pa·s to 7×10 4 Complex viscosity in Pa·s.

38. The chewing gum base of claim 1, wherein said chewing gum base comprises at least 20% by weight of said copolymer.

39. The chewing gum base according to claim 38, wherein the chewing gum base comprises 40 to 70 wt% of the copolymer.

40. The chewing gum base of claim 1 or 2, further comprising at least one additional non-petroleum based ingredient selected from the group consisting of fillers, minerals, fats, emulsifiers, natural waxes, and combinations thereof.

41. The chewing gum base according to claim 40, wherein said chewing gum base comprises at least 1% by weight of said at least one additional non-petroleum based ingredient.

42. The chewing gum base of claim 1, wherein the chewing gum base comprises 30% by weight or less of a petroleum-based polymer.

43. The chewing gum base of claim 42, wherein the chewing gum base is free of petroleum-based polymers.

44. The chewing gum base according to claim 42 or 43, wherein the petroleum-based polymer is selected from the group consisting of butyl rubber, polyisobutylene, butadiene-styrene copolymers, vinyl polymer elastomers, polybutadiene, polyterpene resins, and combinations thereof.

45. The chewing gum base of claim 1, wherein the chewing gum base comprises 10 wt% or less of a tackifier.

46. ​​The chewing gum base of claim 45, wherein the chewing gum base comprises 5 wt% or less of a tackifier.

47. A chewing gum comprising at least one sweetener, at least one flavoring agent and a chewing gum base according to any one of claims 1-46.

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