Citrus fruit skin composition

Abstract

To provide a composition in a paste or puree form obtained using a citrus fruit skin part, which is an unused resource, the composition having a little citral deterioration smell even when preserved for a long period of time, exhibiting an aroma and a flavor like citruses, and having no bitter taste.SOLUTION: A citrus fruit skin composition has been found which generates no off-flavor even when preserved for a long period of time while exhibiting a flavor like citruses with aroma components other than citral, by turning hard citrus fruit skin into a paste form by adjustment of heating temperature and heating time under a constant condition of a pH value and reducing the citral during the production process.SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to a paste-like or puree-like composition that uses citrus peel, which is an unused resource, has little deterioration odor of citral even after long-term storage, exhibits a citrus-like aroma and flavor, and has no bitterness.

Background Art

[0002] Citrus fruits that exhibit a gorgeous and refreshing aroma are used as fragrance raw materials for foods and cosmetics. The aroma components of citrus fruits are more contained in the peel part than in the pulp part. However, the flavedo that forms the outside of the peel part has low processing suitability because it is a strong tissue in which pectin and calcium are bound. In addition, citral, which is the main aroma component, accumulates in the oil cells of the flavedo. However, citral is chemically unstable and deteriorates by heat, light, and oxygen to become off-flavor substances such as p-cresol, p-methylacetophenone, and p-cymene. Therefore, it is difficult to process and control the quality of foods and cosmetics that store citrus peels for a long time, and the pulp part is often used rather than the peel part, and the peel part has been left as an unused resource.

[0003] However, if the peel part is cut into slices or dice, it can be used for foods and beverages that retain the texture of the peel, such as jam, candied fruit, and dried fruit. Non-Patent Document 1 discloses a method for producing marmalade in which the peels of yuzu, summer orange, and lemon are immersed in a citric acid solution with a pH of 2.0-2.7 and subjected to high-pressure heat treatment. In this document, while hydrolyzing the bond between pectin and calcium in the peel, the pH value of the citric acid solution is examined so as not to decompose the pectin that solidifies the marmalade, and the optimum pH is 2.7 for yuzu and 2.0 for lemon. In addition, it has been reported that when heat treatment is performed to soften the peel, the bitter components derived from the peel are intensified or the original aroma and flavor are lost. However, the suppression of the deterioration odor of citral has not been studied.

[0004] Methods for suppressing the off-flavor odor of citral mainly involve methods for inhibiting the generation of off-flavor substances and methods for masking them.

[0005] Examples of citral degradation inhibitors include theanaphthoquinones obtained by oxidizing theaflavins described in Patent Document 1, and one or more plant extracts and / or purified products thereof selected from the group consisting of plants of the genera Scombere, Araucariaceae, Pedicularis, Rubus, Gnetum, Scutellaria, Celastrus, Dioscorea, Chucrasia, and Ternstroemia, described in Patent Document 2. Furthermore, Patent Document 3 reports olive fruit extract, or a mixture of the olive fruit extract and one or more selected from bilberry extract, amla extract, rubus extract, red wine mash extract, and cranberry extract, as a citral degradation inhibitor to effectively suppress the degradation of citral and leave a significant amount of citral remaining.

[0006] Masking agents include those described in Patent Document 4, which contain one or more selected from the group consisting of ethyl pyruvate, methyl jasmonate, methyl dihydro jasmonate, diethyl malonate, methyl beta-naphthyl ketone, maltol isobutyrate, menthol, lauric acid, acetoin, cinnamyl acetate, benzyl acetate, and α-terpineol. Patent Document 5 reports cubebol, which can mask both trans-2-nonenal and off-flavor substances produced during the wort preparation process of beer-flavored beverages, and its degradation product, δ-cadinene.

[0007] In contrast to these prior arts, Patent Document 6 discloses an alcoholic beverage that, instead of suppressing or masking off-flavors, keeps the citral content low and adjusts the sweetness, sugar-acid ratio, and alcohol content in the beverage to a specific range, thereby providing a strong lemon-like flavor despite a low citral content. [Prior art documents] [Patent Documents]

[0008] [Patent Document 1] WO2021-019763 [Patent Document 2] Japanese Patent Publication No. 2020-094182 [Patent Document 3] Japanese Patent Publication No. 2018-029576 [Patent Document 4] Japanese Patent Publication No. 2019-094507 [Patent Document 5] Japanese Patent Publication No. 2019-080579 [Patent Document 6] Japanese Patent Publication No. 2018-108097 [Non-patent literature]

[0009] [Non-Patent Document 1] ▲Hiroko Kuwata: A Study on the Cooking and Processing Characteristics of Citrus Fruits, Journal of the Japanese Society for Food Science and Technology, Vol.48, No.2, pp87-94, 2015. [Overview of the Initiative] [Problems that the invention aims to solve]

[0010] The problem that this invention aims to solve is to provide a paste-like or puree-like composition that uses the unused resource of citrus peel, exhibits a citrus-like aroma and flavor, has little citral degradation odor even after long-term storage, and is free of bitterness. [Means for solving the problem]

[0011] As a result of diligent research to solve the above problems, the present inventors have discovered a citrus peel composition that, by adjusting the heating temperature and heating time under certain pH conditions, can transform hard citrus peel into a paste, reduces citral during the manufacturing process, exhibits a citrus-like flavor from other aromatic components, and does not produce off-flavors even after long-term storage, thus leading to the present invention.

[0012] In other words, the present invention is (1) The citrus peel composition is obtained by subjecting citrus peel to a heat treatment under the conditions of a pH of 2.5 or more and 3.5 or less, a heating temperature of 75°C or more and less than 120°C, and a heating time of 10 minutes or more and less than 100 minutes, and the citrus peel has a penetration stress of 4 Newtons or less. (2) The citrus peel composition according to (1) above, which does not contain citral, contains p-cymene, and contains any one or more of limonene, β-pinene, or γ-terpinene. It is provided. [Effect of the Invention]

[0013] According to the present invention, by adjusting the heating temperature and heating time under certain pH value conditions, hard citrus peel can be changed into a paste or puree form. While reducing citral during the manufacturing process, the composition exhibits a citrus-like flavor with other aroma components. Since the composition does not exhibit bitterness even during heat treatment, it is possible to impart a rich and refreshing aroma and flavor of citrus even when added to breads and the like with delicate taste qualities. [Brief Description of the Drawings]

[0014] [Figure 1] The figure shows the sensory evaluation results when the citrus peel composition according to the present invention is added to bread. [Embodiments for Carrying Out the Invention]

[0015] Hereinafter, the present invention will be described in detail. The citrus peel composition of the present invention is a processed product obtained by heating and stirring the peel part of citrus in a low pH environment to a paste or puree form, and exhibits a preferable flavor peculiar to citrus even when stored for a long time. The preferable flavor peculiar to citrus means a rich and refreshing aroma.

[0016] The citrus fruits used in the present invention include tangelo fruits such as Seminole, AgriFruit, and Tangelo; hybrid citrus fruits such as Shiranuhi (Decopon), Natsumikan, Hassaku, Hyuganatsu, and Sweety; orange fruits such as Valencia orange, Navel orange, Blood orange, Jaffa orange, and Bergamot; grapefruit fruits such as grapefruit and orangelo; acid citrus fruits such as lime, sudachi, daidai, yuzu, kabosu, sudachi, bushukan, citron, and lemon; tangor fruits such as iyo-kan and tankan; buntan fruits such as buntan; mandarin oranges such as mandarin orange, unshu mikan, ponkan, and kishu mikan; and kumquat fruits such as kumquat. In the present invention, acid citrus fruits with a high citral content are desirable, and especially lemon is preferably used. These citrus fruits may be used alone or in combination of multiple species.

[0017] Among the plant bodies composed of fruits (including the parts composed of the fruit skin, pulp, and seeds), branches, leaves, flowers, buds, roots, etc., the fruit part of the citrus fruits used in the present invention is used. In the present invention, it is preferable to use the fruit skin part of the fruit. The fruits of the citrus fruits used in the present invention only need to have reached the maturity suitable for use in beverages or foods, and any of early picking, harvest-appropriate period, and fully ripe period can be used.

[0018] Among the citrus fruits used in the present invention, it is particularly preferable to use lemon. The lemon used in the present invention is a plant belonging to the genus Citrus in the family Rutaceae, and its scientific name is Citrus limon. Its origin is the Himalayas in eastern India, but currently, Europe and the United States are the main producing countries, and it is also cultivated in Japan. The variety is not particularly limited, and in addition to Lisbon, Eureka, Villa Franca, Genoa, and Ponderosa, etc., varieties hybridized with other Rutaceae plants (such as Meyer lemon, Saipan lemon, and sweet lemonade) can also be used. Also, the production area is not particularly limited, and examples include China, India, Mexico, Argentina, Brazil, the United States, Turkey, Spain, Iran, Italy, Chile, Japan, etc. The production area of the lemon used in the present invention is not particularly limited, but lemons produced in Japan or Italy are preferable.

[0019] In this invention, the peel of a lemon fruit is particularly preferred. Lemon peel is the part of a fresh lemon fruit from which the pulp, seeds, segmental membranes, and pulp surrounding the pulp have been removed. It may be obtained by manually removing parts other than the peel, or it may be obtained industrially using an outer peeling machine, a fruit splitter, an inner peeling machine, a juicer, etc. It may also contain pulp and juice that may be mixed in during the peeling process. The lemon peel does not need to maintain its perfect shape; it may be physically processed to change its shape, form, and physical properties, such as being diced, chopped, or pulped. Furthermore, to avoid spoilage and decay caused by oxygen, light, heat, microorganisms, endogenous enzymes, etc., it is preferable that the lemon peel obtained after peeling is immediately subjected to heating and stirring to produce lemon puree, or processed and distributed in a form that allows for long-term storage. Forms that allow for long-term storage include refrigeration, freezing, freeze-drying, and dried powder. In the present invention, any of these forms may be used, but frozen lemon peel is preferably used.

[0020] In this invention, the composition is obtained by adding water to citrus fruits and heating and stirring until it becomes a smooth and uniform puree. The mixing ratio of citrus fruits to water is not particularly limited as long as it becomes a uniform puree. To give a more specific example, when using lemon peel, although not limited to this specific example, it is preferable to use 100-1000 parts by weight of water, preferably 200-800 parts by weight, more preferably 300-700 parts by weight, and even more preferably 400-600 parts by weight, per 100 parts by weight of lemon peel. If the amount of water is increased to more than 1000 parts by weight, the additive effect of the composition is difficult to obtain, and if the amount of water is less than 100 parts by weight, problems such as the lemon peel burning during heating and stirring, or inability to stir and thus not being able to obtain a smooth and uniform composition tend to occur. The stirring speed is not particularly limited, but any speed at which the citrus peel and water are thoroughly mixed without settling or burning is acceptable. The speed may be adjusted as appropriate depending on the inner diameter and depth of the container holding the mixture, and the clearance between the stirring blade and the inner diameter of the container.

[0021] In the present invention, in the step of heating and stirring the citrus peel, the pectin in the lemon peel may be enzymatically decomposed before heating and stirring in order to promote and assist in the softening of the citrus peel. For example, when using pectinase, enzymes with activity such as polygalacturonase, pectin lyase, pectin esterase, and pectin methylesterase can be used. Pectinase is known to be contained in bacteria, molds, yeasts, higher plants, snails, etc., and in the present invention, pectinase collected from these and other organisms can be widely used. In addition, commercially available pectinase preparations can also be used. Examples of commercially available pectinase preparations include Sucrase® A, Sucrase® N, Sucrase® S (all manufactured by Mitsubishi Chemical Foods), Pectinex Ultra® SP-L (manufactured by Novo Nordics A / S), Meiseraze® (manufactured by Meiji Seika Pharma), Ultrazyme® (manufactured by Novo Nordics A / S), Neurase F®, Pectinase G "Amano" (all manufactured by Amano Enzyme), and Sumizyme® SPG (manufactured by Shin Nippon Chemical Industries). The amount of pectinase used is not particularly limited and varies depending on the type and properties of the lemon peel used, but it is usually used in the range of 0.001 to 5% by weight relative to the lemon peel, preferably 0.01 to 1% by weight. Furthermore, in the reaction using pectinase, other enzymes with pectinase activity, such as hemicellulases, xylases, mannanases, or cellulases, may be used in combination with the pectinase enzyme. Examples include sucrase X (Mitsubishi Chemical Foods), hemicellulase "Amano" 90 (Amano Enzyme Co., Ltd.), and sumizyme ACH (Shin Nippon Chemical Industries, Ltd.).

[0022] In the present invention, in the step of heating and stirring citrus peel, an acid and / or acidic salt may be added and heated and stirred in order to promote and assist in the softening of the citrus peel. The addition method may be by sprinkling it directly onto the citrus peel or by dissolving it in water and then adding it. Examples of acids and / or acidic salts include organic acids such as citric acid, succinic acid, lactic acid, malic acid, tartaric acid, and gluconic acid, as well as inorganic acids such as phosphoric acid and hydrochloric acid, and their salts, but are not limited to these. The amount of acid or acidic salt used varies depending on the type and properties of the citrus peel used and the type of acid and / or acidic salt used, and cannot be stated in general terms, but is 0.1 to 20 parts by weight, preferably 1 to 10 parts by weight, per 100 parts by weight of citrus peel. After immersing the citrus peel in the acidic solution, heating and stirring may be started immediately, or the peel may be stored for a certain period of time at a temperature at which acid does not precipitate before heating and stirring. The temperature during immersion should be such that no acid precipitates, preferably 30-60°C, more preferably 40-60°C, and even more preferably 50-60°C.

[0023] In the present invention, the heating and stirring of citrus peel is not particularly limited in terms of the shape of the stirring blade, the clearance between the stirring blade and the inner wall of the tank, or the stirring speed, as long as the quality of the citrus peel composition is not significantly impaired. Undesirable changes in the quality of the citrus peel composition include charring due to excessive heating, loss of lemon flavor, browning of the color, and changes in physical properties such as viscosity. The heating temperature is, for example, 50°C-120°C, preferably 60-110°C, and more preferably 70-100°C. The stirring time should be such that the pectin of the citrus peel is no longer found in the composition and the penetration stress on a rod-shaped hardness tester is preferably 10 or less, more preferably 7 or less, and even more preferably 4 or less, for example, 5 minutes to 6 hours is a guideline, preferably 10 minutes to 4 hours, and more preferably 10 minutes to 2 hours. The stirring operation method may be continuous stirring or intermittent stirring, and is not particularly limited. When preparing citrus peel compositions at a laboratory level, for example, citrus peels and water can be weighed into a stainless steel beaker and heated in a constant-temperature bath while stirring with a stirrer to make a puree of the citrus peels. At an industrial level, citrus peels and water are placed in a temperature-controlled tank and heated while stirring with a stirring blade to obtain a puree or paste-like citrus peel composition.

[0024] In the present invention, the pH value during heating and stirring of citrus peel is preferably in the acidic range, specifically, pH 2.3 to 4, more preferably 2.5 to 3.5. If the pH value is lower than 2.3, the flavor of foods using the citrus peel composition will be strongly acidic, making it difficult to use as an ingredient. If the pH value is higher than 4, the citrus peel will remain hard and cannot be made into a paste or puree.

[0025] In this invention, the aroma components contained in the citrus peel composition were qualitatively determined by gas chromatography-mass spectrometry. As a pretreatment of the analytical sample, the citrus peel composition after heat treatment was freeze-dried and pulverized in a kitchen mixer. 5 g of the pulverized citrus peel composition was mixed with 50 mL of an extraction solvent of pentane:dichloromethane = 7:3 and solvent extraction was performed. Cyclohexanol was used as the internal standard, and 5 μL was sealed in a GC vial together with the sample. The analytical sample after solvent extraction was sonicated (30 minutes) and shaken (30°C, 100 rpm, 2 hours). Before dispensing into a GC vial, the analytical sample was filtered by suction, and the filtrate was further purified by filtering through a solvent-resistant disc filter with a pore size of 45 μm. The analytical conditions for the GC / MS method in this invention are described below. Analytical equipment: GC unit - 7980A (Agilent Technologies, Inc.) MS-700B (Agilent Technologies, Inc.) Analytical column: TC WAX (GL Sciences Co., Ltd., 60m x 0.25mm id, film thickness 0.25μm) Mobile phase: He (Helium) Syringe: DVB / Carboxen / PDMS (SPELCO) Injection: Heater 230°C, pressure 530.6 psi, total flow 22.8 mL / min, septum purge flow rate 3 mL / min, mode split, split ratio 10:1, split flow rate 18.0 mL / min Heating conditions: 40℃ for 5 minutes → 2℃ / min → 100℃ → 4℃ / min → 240℃ for 10 minutes Ion source temperature: 230℃ Ionization voltage: 70 eV Identification: Matched against the NIST database using the PBM algorithm. [Examples]

[0026] The present invention will be specifically described below with reference to examples and comparative examples. The present invention is not limited to these.

[0027] (Example 1: Method - Investigation of heating temperature in the method for producing citrus peel composition) The effects of heating temperature on the production method of citrus peel compositions were compared, specifically in terms of peel softening and changes in aroma. The composition was prepared using 100g of lemon peel and 400g of water as raw materials. These were weighed into a stainless steel beaker and heated in a heated water bath for 20 minutes. No pH adjustment was performed during heating. A portion of the composition after the heating reaction was completed was taken, and the softening of the fruit peel was examined. The degree of softening was determined by measuring the penetration stress using a rod-type hardness tester, and the properties of the composition were visually confirmed after it was ground in a kitchen mixer at a constant strength and for a certain period of time. Furthermore, a portion of the composition after the heating reaction was completed was separated, and the change in aroma was compared by sensory evaluation. The citrus peel composition was stored at 40°C, where deterioration is likely to accelerate, and evaluated from the next day to 7 days later. The evaluation item was "lemon-like aroma," defined as a "lemon-like aroma" that exhibits a bright and refreshing scent and a sweet scent without irritating odor. ◎ was used to indicate a strong smell, ○ to indicate a pleasant smell, △ to indicate a slight smell, and × to indicate no smell at all or an unpleasant smell.

[0028] (Example 1 Result 1 Effect of heating temperature on the physical properties of citrus peel) Table 1 shows the penetration stress and properties after mixing with a mixer. At a heating temperature of 50°C (comparison group 1), the penetration stress was high, and even after mixing with a cooking mixer, a large amount of hard, large pieces of peel tissue were observed, so a paste-like or puree-like citrus peel composition could not be obtained. At heating temperatures between 100°C and 121°C (experimental group 1, experimental group 2, comparison group 2), the penetration stress was 5 or less, and it was easily made into a paste-like or puree-like consistency with a cooking mixer. At a heating temperature of 75°C (experimental group 1), the penetration stress was 6.3, and after mixing with a cooking mixer, some small pieces of peel tissue were observed, but it was suggested that they could be crushed by extending the heating time.

[0029] [Table 1]

[0030] (Example 1, Result 2: Effect of heating temperature on the sensory properties of citrus peel) Tables 2 and 3 show the sensory evaluation results. Table 2 shows the evaluation results the day after the citrus peel composition was prepared (1 day after storage), and Table 3 shows the evaluation results after 7 days at a storage temperature of 40°C. The results after one day of storage showed that the lower the heating temperature, the stronger the lemon-like aroma was perceived. After seven days of storage, there were no significant differences between the test sections other than 121°C (comparison section 2), and the lemon-like aroma was well maintained.

[0031] From the above, it was found that in the method for producing the citrus peel composition, when the heating temperature was higher than 75°C but lower than 121°C, the citrus peel was crushed into a paste or puree and retained its lemon-like aroma well. In Experiment 1, some pieces of peel tissue were still observed even after stirring with a cooking mixer, but it was suggested that extending the heating time to 20 minutes or more could result in a paste or puree. Even when an accelerated test (abuse test) was conducted at a storage temperature of 40°C, the lemon-like aroma was well retained for up to 7 days, indicating that the flavor can be preserved for a longer period by storing it in a cool, dark place.

[0032] [Table 2]

[0033] [Table 3]

[0034] (Example 2: Method - Investigation of heating time in the method for producing citrus peel composition) The effects of heating time and temperature on the production method of citrus peel compositions were compared, specifically regarding the softening of the peel and the change in aroma. Similar to Example 1, the composition was prepared using 100 g of lemon peel and 400 g of water as raw materials. These were weighed into a stainless steel beaker and heated in a heated water bath or autoclave under the conditions shown in Table 4. The pH was adjusted to a range of 2.8 ± 0.05. The physical properties of the citrus peel composition after the heating reaction were evaluated in the same manner as in Example 1. Sensory evaluation was performed only on the test groups that were in paste or puree form, and was conducted in the same manner as in Example 1, except that it was performed under accelerated testing conditions (stored at 40°C) and evaluated after 3 and 7 days of storage.

[0035] [Table 4]

[0036] (Example 2 Result 1: Effect of heating time and temperature on the physical properties of citrus peel) Table 5 shows the penetration stress and properties after mixing with a mixer. At a heating temperature of 50°C (comparison groups 3 and 4), the penetration stress was somewhat high, and a few small pieces of fruit peel tissue were observed after mixing with a cooking mixer. By combining heating temperatures of 75-120°C and heating times of 10-120 minutes, the penetration stress decreased, and the mixture easily became a paste or puree with a cooking mixer.

[0037] [Table 5]

[0038] (Example 2, Result 2: Effects of heating time and temperature on the sensory properties of citrus peel) Tables 6 and 7 show the sensory evaluation results. Table 6 shows the evaluation results of the citrus peel composition after 3 days at a storage temperature of 40°C, and Table 7 shows the evaluation results after 7 days under the same storage conditions. Comparative groups 3 and 4, which were heated at a temperature of 50°C, were not evaluated because fragments of peel tissue remained at the end. The results after 3 days of storage showed that the lemon-like aroma was retained when heated to 75°C for 60 minutes or more. However, heating at 100°C for 120 minutes (comparison group 6) resulted in a less noticeable lemon-like aroma and a somewhat unpleasant smell. The results after 7 days of storage did not differ significantly from those after 3 days, but the sample heated at 100°C for 100 minutes (comparison group 5) showed a tendency to have a less noticeable lemon-like aroma. In all test groups except for comparison groups 5 and 6, the lemon-like aroma was well maintained even after 7 days of storage, indicating that it can be stored for a long period of time.

[0039] [Table 6]

[0040] [Table 7]

[0041] From the above, it was found that in the method for producing the citrus peel composition, when the heating temperature was 100°C or higher but less than 121°C, the citrus peel was crushed into a paste or puree and retained its lemon-like aroma well. Even when an accelerated test (abuse test) was conducted at a storage temperature of 40°C, the lemon-like aroma was well retained for up to 7 days, indicating that the flavor can be preserved for an even longer period by storing it in a cool, dark place.

[0042] (Example 3: Method - Analysis of aroma components of citrus peel composition) Aroma component analysis was performed on citrus peel compositions heated at different temperatures (comparative group 1, experimental group 3, experimental group 6, and comparative group 2). Each composition was stored in a cool, dark place after preparation.

[0043] (Example 3: Results - Analysis of aroma components of citrus peel composition) Table 8 shows the peak areas after qualitative analysis for some of the major aroma components detected from citrus peel compositions. Comparison Group 1: Citral was not detected, suggesting that most of it had decomposed. Limonene, β-pinene, and γ-terpinene, which are lemon-like aroma components, were detected and are thought to contribute to the lemon-like scent. p-cymene, which is considered to be a degraded odor, was not detected. Experiment 3: No citral was detected, suggesting that most of it had decomposed. Limonene, β-pinene, and γ-terpinene, which are lemon-like aroma components, were detected and were thought to contribute to the lemon-like scent. Although p-cymene, which is considered an off-odor, was detected, many panels evaluated it as having a good lemon-like scent in the sensory evaluation, suggesting that it was masked by limonene, β-pinene, and γ-terpinene. Experiment 6: No citral was detected, suggesting that most of it had decomposed. Limonene, β-pinene, and γ-terpinene, which are lemon-like aroma components, were detected and were thought to contribute to the lemon-like scent. Although p-cymene, which is considered an off-odor, was detected, many panels evaluated it as having a good lemon-like scent in the sensory evaluation, suggesting that it was masked by limonene, β-pinene, and γ-terpinene. Comparison Group 2: Citral was not detected, suggesting that most of it had been decomposed. Limonene, β-pinene, and γ-terpinene, which are lemon-like aroma components, were detected and thought to contribute to the lemon-like scent, but their peak areas were smaller than in the other test groups. p-cymene, which is considered to be a source of off-odor, was not detected. Since many panels had difficulty perceiving a lemon-like scent in the sensory evaluation, it was thought that aroma components such as limonene, β-pinene, and γ-terpinene were reduced by heating, resulting in an overall weakening of the aroma.

[0044] [Table 8]

[0045] (Example 4: Method for evaluating the taste quality of citrus peel composition; bread-making method) The taste quality of citrus peel compositions was investigated through sensory evaluation when added to white bread. Lemon flavoring and lemon juice were used as comparative ingredients. The amount added was adjusted according to the physical properties of the bread dough. White bread (straight dough method) was prepared according to the following procedure. In formulations containing citrus peel composition and juice, these ingredients were pre-mixed with water before use. Similarly, in formulations containing powdered flavoring, these were pre-mixed with strong flour before use. Specifically, strong flour, sugar, salt, skim milk powder, yeast (Dia Yeast, Mitsubishi Corporation Life Sciences Co., Ltd.), yeast food (Pan Dia C-500, Mitsubishi Corporation Life Sciences Co., Ltd.), water, citrus peel composition and its comparative ingredients were weighed and kneaded in a vertical mixer. The mixing speed of the mixer was adjusted as needed, and after confirming that gluten had formed in the dough, shortening was added and kneaded again. Mixing was stopped after confirming that the dough and shortening were thoroughly mixed and that gluten had formed again in the dough, and the dough temperature at this time was defined as the kneading temperature. In addition, the kneading temperature was adjusted to within 28 ± 0.5℃ by cooling the dough as needed during mixing. The kneaded dough was subjected to primary fermentation in a constant temperature bath. After primary fermentation, the dough was divided, rounded, and allowed to rest during bench time. After bench time, the rounded dough was shaped using a molder, and 440g per loaf was placed in a Pullman loaf pan. After shaping, the dough underwent a second fermentation in a proofing chamber, and after fermentation was complete, it was baked in a reel oven or a fixed oven. The baked bread was cooled at room temperature for 90 minutes, then placed in a plastic bag and stored in a constant temperature chamber maintained at 25°C until ready for evaluation testing.

[0046] [Table 9]

[0047] [Table 10]

[0048] (Example 4: Method for evaluating the taste quality of citrus peel composition - Sensory evaluation method) A sensory evaluation was conducted on bread baked the day after it was delivered. The evaluation criteria were "citrus aroma," "citrus flavor perceived in the mouth," and "bitterness," and were quantified on a 7-point scale. For each taste, a score greater than 4 was chosen when the taste was perceived as stronger than the additive-free bread (which was assigned a score of 4), and a score less than 4 was chosen when the taste was perceived as weaker. The sensory evaluation was conducted by a panel of eight experts.

[0049] (Example 4: Results - Taste quality evaluation of citrus peel composition) The results of the sensory evaluation are shown in Figure 8. In control group 3, which had the citrus peel composition added, the "citrus aroma" was weaker than in control group 7 (which had added flavoring), but significantly higher (p<0.01) than in the control group without additives and control group 8 (which had added fruit juice). In terms of "citrus flavor perceived in the mouth," it was weaker than in the flavoring-added group (control group 7), but the effect of the additive was significantly higher than that of fruit juice. "Bitterness" was milder than in control groups 7 and 8 (which had added flavoring and fruit juice), and significantly weaker than control group 7. It was considered that the generation of bitterness due to heating was suppressed during the manufacturing process of the citrus peel composition. [Industrial applicability]

[0050] As described above, according to the present invention, hard citrus peels can be transformed into a paste or puree by adjusting the heating temperature and heating time under constant pH conditions. The composition exhibits a citrus-like flavor through other aromatic components, while reducing citral during the manufacturing process. Since the composition does not exhibit bitterness despite being heat-treated, it can impart a bright and refreshing citrus aroma and flavor even when added to delicate foods such as bread.

Claims

1. A heat-treated citrus peel composition, characterized by having a penetration stress of 4 Newtons or less, under conditions of a pH of 2.5 or more and 3.5 or less, at 75°C or more and less than 120°C, for 10 minutes or more and less than 100 minutes.

2. The citrus peel composition of claim 1, which is free of citral, contains p-cymene, and contains any one or more of limonene, β-pinene, or γ-terpinene.

3. A method for producing a citrus peel composition, comprising subjecting citrus peel to a heat treatment at 75°C or higher but lower than 120°C for 10 minutes or longer but less than 100 minutes under conditions of a pH of 2.5 or higher but lower than 3.5.