Chinese yam cake with composite sour system for synergistically activating salivary amylase and preparation method of Chinese yam cake

Abstract

The invention discloses a Chinese yam cake with a compound sour system for synergistically activating salivary amylase and a preparation method thereof. The Chinese yam cake comprises the following raw materials: Chinese yam, konjaku flour or oligosaccharide, a sweetening agent, a gelling agent, malic acid, citric acid, hawthorn, dark plum and water. The main structure matrix is jointly constructed by Chinese yam powder, konjaku flour / oligosaccharide and gels to form a cake body base; a composite sour system is uniformly distributed in a gel network, a complementary system is formed through superposition of various organic acids, and the composite sour system has good buffer capacity, can maintain weak acidic pH in the oral cavity and activate the activity of alpha-amylase without inhibition, and is different from the problem that a single acid system is prone to'excessive acid 'enzyme inhibition; and an optimal reaction microenvironment is provided for salivary enzyme activity, and multi-level taste experience is also provided. The gel characteristics of Chinese yam mucoprotein and oligosaccharide are fused to form a sour slow-release matrix, so that sour release presents a dynamic curve of front fast-middle stable-rear slow, the flavor release time is prolonged, and the continuous perception of the oral cavity is enhanced. The enzymatic reaction in the oral cavity is prolonged.

Description

Technical Field

[0001] This invention relates to the field of functional food processing technology, and more particularly to a yam product and its preparation method that utilizes a complex acidity system to regulate the oral microenvironment and synergistically activate salivary amylase activity. Background Technology

[0002] Yam is a traditional Chinese medicinal and edible plant, rich in various functional components such as soluble starch, mucoprotein, saponins, polysaccharides, and dietary fiber. It not only nourishes the spleen and stomach, moistens the lungs and nourishes yin, but modern nutritional research has also confirmed its antioxidant, blood sugar regulating, and immune-boosting effects. Therefore, yam is widely used as a core ingredient in health foods and functional foods, particularly in Chinese pastries, dietary supplements, and ready-to-eat health foods.

[0003] Currently, most mainstream yam cake products on the market are positioned around the core characteristics of being "soft, glutinous, and sweet," using added sugars and viscous substances (such as konjac powder, agar, and glutinous rice flour) to create a delicate and soft texture, enhancing the eating experience. However, these products generally suffer from the following problems: (i) The flavor is simple and the oral stimulation is weak. Traditional yam cake products are generally too sweet, have a monotonous taste, and release flavor slowly. They lack sensory rhythm changes during consumption, making it difficult to form a taste memory or sustained appeal. This can easily lead to a "sweet and cloying" or "taste-tiring" experience, and they are particularly unattractive to young consumers and health-conscious individuals.

[0004] (ii) Lack of functional coordination within the oral cavity and absence of physiological response mechanisms Modern food science research indicates that the "first impression" of food in the mouth not only determines the flavor experience but also directly affects satiety, digestive efficiency, and nutrient absorption. Saliva secretion, oral pH, and enzymatic hydrolysis activity are key regulatory factors.

[0005] α-Amylase in saliva is a core enzyme in primary oral digestion, mainly catalyzing the hydrolysis of polysaccharides (such as starch) into oligosaccharides such as maltose, preparing them for absorption in the gastrointestinal tract. Studies have shown that the activity of this enzyme is extremely sensitive to pH, with its optimal activity range being pH 6.2-6.8. Many traditional pastries or acidic beverages, due to their low pH or unstable systems, may inhibit salivary enzyme activity, reducing their initial digestive efficiency and flavor release.

[0006] However, currently no yam cake products on the market focus on the oral microecological mechanism of "salicylic enzyme synergistic activation". Product design remains at the level of texture improvement and single flavor adjustment, lacking a systematic consideration of the oral-digestive linkage mechanism.

[0007] (III) The functional potential of the complex acidity system has not yet been realized in such products. Complex acidity systems refer to flavor systems that combine multiple organic acids (such as malic acid, citric acid, lactic acid, and hawthorn acid) with natural fruit acid extracts (such as plum, hawthorn, and currant) to create a layered, buffering, and pH-regulating flavor profile. This system has already been applied in jellies, beverages, and functional gummies to create a tart-sweet taste experience and enhances saliva production through the acid-saliva reflex, thereby improving sensory pleasure.

[0008] However, there is currently no mature solution in yam products that combines a complex acidic taste system with saliva pH regulation and α-amylase activity control, and there is a lack of related application research or industrialization cases. Traditional applications mostly rely on sweetness and gelatinized texture, and have not yet integrated "sensory regulation-physiological activation-nutrient release" into one.

[0009] (iv) Existing technologies lack scientific verification support, and mechanism research is lagging behind. There is currently a lack of patents and literature regarding the application of complex acidity systems in enhancing salivary enzyme activity and promoting preliminary digestion. Existing research largely focuses on sensory descriptions or nutritional label optimization, lacking systematic validation through simulated oral response models, and has not conducted experimental methods such as the DNS method, simulated digestive fluids, and flavor release kinetics to confirm its mechanism of action.

[0010] Based on the above analysis, developing a novel yam cake product that combines a complex acidity system to regulate pH, enhance flavor perception, and synergistically activate salivary enzyme function has the following necessity and cutting-edge value: ① It transforms from "passive flavor" to "active sensory stimulation + functional synergy"; ② It fills the gap in the application of the complex acidity system and salivary enzyme linkage mechanism in traditional yam foods; ③ It establishes a complete product mechanism verification path (preparation - in vitro experiment - oral simulation); ④ It meets the research and development trend of "delicious + useful + mechanism-based" in health functional foods. Summary of the Invention

[0011] The purpose of this invention is to address the shortcomings of existing technologies by providing a yam cake product and its preparation method that utilizes a complex acidic system in synergistic activation of salivary amylase. This aims to solve the problems of existing yam cake products having a single flavor profile, insufficient flavor release in the oral cavity, and a lack of a synergistic mechanism for regulating salivary amylase activity and oral function. Specifically, this invention constructs a complex acidic system with malic acid, citric acid, hawthorn, and dried plum as its core components, precisely controlling the slightly acidic pH environment of the yam cake in the oral cavity, placing it within the optimal activity range of salivary amylase (pH 6.2–6.8).

[0012] This application provides a yam cake with a complex acidic system synergistically activated by salivary amylase, the raw materials of which include yam, konjac flour or oligosaccharides, sweetener, gelling agent, malic acid, citric acid, hawthorn, dried plum and water.

[0013] In one embodiment, the sweetener is a food-grade sugar alcohol (such as maltitol).

[0014] In one embodiment, the gelling agent includes one or more of agar, pectin, and carrageenan.

[0015] In one embodiment, the yam is in the form of yam pulp or yam powder; and / or the hawthorn is in the form of hawthorn pulp; and / or the dried plum is in the form of dried plum juice.

[0016] Further, the ingredients include 80-100 parts yam, 0.2-0.8 parts konjac powder or oligosaccharides, 0.1-0.6 parts gelling agent, 0.02-0.1 parts malic acid, 0.1-0.2 parts citric acid, 2-8 parts hawthorn, and 2-8 parts dried plum. Still further, 5-10 parts sweetener and appropriate amount of water.

[0017] Preferably, the yam cake maintains a slightly acidic pH in the oral cavity, pH 6.2–6.8; further preferably, pH 6.2–6.5.

[0018] This application provides a method for preparing yam cake with a complex acidic system synergistically activated by salivary amylase. The raw materials include yam, konjac flour or oligosaccharides, sweetener, gelling agent, malic acid, citric acid, hawthorn, plum juice and water.

[0019] In one embodiment, the sweetener is a food-grade sugar alcohol (such as maltitol).

[0020] In one embodiment, the gelling agent includes one or more of agar, pectin, and carrageenan.

[0021] In one embodiment, the yam is in the form of yam paste; and / or the hawthorn is in the form of hawthorn paste; and / or the dried plum is in the form of dried plum juice.

[0022] Further, the ingredients include 80-100 parts yam, 0.2-0.8 parts konjac powder or oligosaccharides, 0.1-0.6 parts gelling agent, 0.02-0.1 parts malic acid, 0.1-0.2 parts citric acid, 2-8 parts hawthorn, and 2-8 parts dried plum. Still further, 5-10 parts sweetener and appropriate amount of water.

[0023] The preparation steps include: 1. Raw material pretreatment: Thoroughly mix yam powder, konjac powder (or oligosaccharides), sweetener and gelling agent; 2. Acid preparation: Malic acid and citric acid are pre-dissolved, and hawthorn pulp and dried plum juice are taken to adjust the pH of the liquid to 6.2±0.2; 3. Gelatinization: Mix the acid solution with the dry powder, heat and stir to promote gel formation; 4. Filling and Cooling: The hot material is poured into the mold and allowed to cool and solidify. 5. Demolding and Packaging: After natural cooling or refrigeration, demold and package to obtain the finished product.

[0024] Preferably, CaCl2 solution is added before filling and cooling to trigger cross-linking of konjac.

[0025] Preferably, amphiphilic substances, such as amino acids, mono- and diglycerides, are added during the raw material pretreatment.

[0026] Preferably, heat to 85–90°C and stir for 5–10 minutes.

[0027] The beneficial effects of this application are: (1) The main structural matrix is ​​constructed from yam powder, konjac powder / oligosaccharide and gelling agent to form a uniform, plastic, elastic and unbreakable cake base, providing good textural support.

[0028] (2) The complex acidic system (malic acid, citric acid, hawthorn, and dried plum) is evenly distributed in the gel network. Through the superposition of multiple organic acids, a complementary system is formed, which has good buffering capacity. It can maintain a weakly acidic pH in the oral cavity, activate α-amylase activity without inhibiting it, which is different from the problem of single acid systems being "overly acidic" and inhibiting enzymes. The construction of a weakly acidic buffer system (pH controlled at 6.2–6.8) provides the optimal reaction microenvironment for salivary enzyme activity and also provides a multi-layered taste experience (initial acidity – middle freshness – final sweetness). In addition, acidic substances are released in stages during chewing, which synergistically enhances saliva secretion.

[0029] (3) By combining the gel properties of natural mucoprotein from yam with oligosaccharides (or konjac rich in oligosaccharides), a "slow-release acid matrix" is formed, which makes the release of acidity present a dynamic curve of "fast at the beginning, stable in the middle, and slow at the end", prolonging the flavor release time and enhancing the continuous perception in the oral cavity. It also enhances the persistence of flavor and prolongs the enzymatic reaction in the oral cavity.

[0030] In summary, the regulatory targets (pH, enzyme activity, flavor) are achieved through the "natural chewing process" in the mouth, without the need for special operations, and sensory, physiological, and nutritional effects are achieved simultaneously. Attached Figure Description

[0031] Figure 1 Response surface plots of the amount of added plum juice, hawthorn syrup and malic acid to sensory scores.

[0032] Figure 2 This is a standard curve diagram for the DNS method.

[0033] Figure 3 This is a product image. Detailed Implementation

[0034] To facilitate understanding by those skilled in the art, the present invention will be further described below with reference to embodiments. The content mentioned in the embodiments is not intended to limit the present invention.

[0035] Example 1: Preparation of Yam Cake Yam pretreatment Select fresh, disease-free, and moderately mature iron yam, free from mechanical damage. Peel, wash, and slice. Preserve the color with 0.3% citric acid for 3-5 minutes to prevent oxidation and discoloration. Rinse twice to remove the acid. Steam the yam in a pot at 100℃ for 20-25 minutes (until a chopstick can easily pierce it). Add water to the steamed yam (1:1 ratio) and grind it into a fine paste using a colloid mill. Sieve through an 80-mesh sieve.

[0036] Colloid pretreatment 1. Konjac alkaloid activation: Weigh 0.5g of konjac powder, add 30ml of ultrapure water and stir in a 60℃ water bath for 30min. Adjust the pH to 9.0 with calcium hydroxide solution, keep warm at 85℃ for 15min, and then cool to 50℃.

[0037] 2. Agar dissolution: Dissolve 0.3g of agar in 30ml of boiling water, stir magnetically for 10min, and keep the solution temperature at 60℃.

[0038] Preparation of salivating components 1. Plum juice: Take 20g of dried plums and put them into 200ml of water. Boil and concentrate to 50ml. Centrifuge at 4000rpm for 10min. Take the supernatant and adjust the pH to 3.5.

[0039] Remove the pits from fresh hawthorns, steam them at 100℃ for 10 minutes, pulp them, and pass them through a 100-mesh sieve. Adjust the solids content to 20%.

[0040] 2. Acid mixture: Weigh out 0.15g of citric acid and 0.05g of L-malic acid, dissolve them in 2ml of ultrapure water, and vortex repeatedly until dissolved.

[0041] Main matrix mixing Take 100g of yam pulp, add 7.0g of maltitol, 0.2g of monoglyceride, and 0.01g of L-cysteine, and mix thoroughly with a stirrer. Then add activated konjac gum and continue stirring for 1 minute. Next, add agar solution at 60℃ and stir for 30 seconds. Then add the prepared plum juice and mixed acid solution (liquid pH 6.2±0.2), and stir gently to avoid damaging the colloidal structure. Finally, add CaCl2 solution dropwise to trigger konjac cross-linking.

[0042] Shaping and post-processing Pour the well-mixed solution into the mold, press it down and smooth the surface to prevent air bubbles from forming inside. Refrigerate at 4°C for 2 hours, and finally demold.

[0043] Example 2: Optimization of the Complex Acidity System To optimize the proportions of salivating components in the complex sour flavor system, and to maximize the flavor intensity, sweet-sour balance, and flavor duration of the yam cake product while maintaining good texture, this experiment used response surface methodology to analyze the effects of three factors—"plum juice, hawthorn syrup, and malic acid"—on the overall flavor score of the product, constructed a predictive model, and determined the optimal addition ratio.

[0044] Ten healthy adult volunteers, including five boys and five girls, participated in a randomized crossover experiment. Each volunteer was tested sequentially across three groups (with intervals of ≥15 minutes, after rinsing with water). Sensory evaluations were based on sweetness, acidity, and flavor duration.

[0045] Table 1 Flavor Duration and Sweet / Sour Rating index Group A Group B Group C Increase in magnitude (Group C: Group A) Flavor duration (seconds) 18±4 31±3 41±4 228% Acidity rating (1–5) 2.1±0.2 3.8±0.3 4.3±0.3 205% Sweetness rating (1–5) 3.2±0.2 3.7±0.3 4.3±0.3 134% Based on the response surface methodology optimization results, the recommended addition amounts are 5% plum juice, 5% hawthorn syrup, and 0.05g / 100g malic acid.

[0046] Example 3: Texture determination of yam cake This study investigated the relationship between konjac and different gelling agents and the texture of yam cake. Group A consisted of konjac and pectin, Group B of konjac and agar, Group C of konjac, and Group D of konjac and carrageenan. The textural properties of the yam cake were determined using the TPA mode of a food physical property analyzer. A 20g sample of yam cake was placed in the center of a mold, and the screw was tightened to secure the sample. The hardness, elasticity, adhesiveness, chewiness, and resilience of the sample were measured using a P / 36R probe after two pressing cycles. The pre-test rate was 3.0 mm / s, the test rate was 1.0 mm / s, the post-test rate was 1.0 mm / s, the compression ratio was 50%, the trigger force was 5g, and the time interval was 3 s.

[0047] Table 2 Texture properties of different products type Hardness / N Viscosity / g Cohesion / % Elasticity / mm Adhesion / g Chewing properties / (g·mm) A <![CDATA[619.67 ±118.17 a ]]> <![CDATA[90.00±43.86 a ]]> <![CDATA[0.61±0.03 a ]]> <![CDATA[6.41±0.22 a ]]> <![CDATA[382.00 ±85.77 a ]]> <![CDATA[2454.67 ±592.87 a ]]> B <![CDATA[302.33± 43.32 b ]]> <![CDATA[30.33±5.51 abc ]]> <![CDATA[0.55±0.04 ab ]]> <![CDATA[4.47±0.07 b ]]> <![CDATA[166.33 ±14.57 b ]]> <![CDATA[742.00 ±75.50 b ]]> C <![CDATA[237.00±18.19 bcd ]]> <![CDATA[21.33 ±13.43 bcd ]]> <![CDATA[0.27±0.04 d ]]> <![CDATA[1.94±0.27 d ]]> <![CDATA[63.67 ±10.79 bcd ]]> <![CDATA[123.33± 26.10 bcd <!-- 4 -->]]> D <![CDATA[267.67±22.90 bc ]]> <![CDATA[37.67 ±9.87 ab ]]> <![CDATA[0.39±0.03 c ]]> <![CDATA[3.33±0.39 c ]]> <![CDATA[103.00±14.73 bc ]]> <![CDATA[340.00±29.87 bc ]]> Based on the textural results, the synergistic effect of konjac and agar can best improve the textural quality of yam cake, resulting in moderate hardness, good elasticity, high cohesion, and low viscosity, which balances chewiness and comfort. It is suitable for developing functional yam cake products with stable texture and good chewiness.

[0048] Example 4: In vitro simulation experiment of DNS method The determination of reducing sugars is a fundamental method for the quantitative determination of various carbohydrate compounds. Under alkaline conditions, when reducing sugars are heated with 3,5-dinitrosalicylic acid (DNS), the 3,5-dinitrosalicylic acid (DNS) is reduced to 3-amino-5-nitrosalicylic acid (a brownish-red substance), while the reducing sugars are oxidized to sugar acids and other products. Within a certain range, the concentration of reducing sugars is directly proportional to the intensity of the brownish-red color of 3-amino-5-nitrosalicylic acid (the brownish-red substance). Using a visible spectrophotometer, the absorbance of the brownish-red substance is measured at a wavelength of 540 nm, and the content of reducing sugars in the sample can be determined by referring to a standard curve.

[0049] Solution preparation: 3,5-Dinitrosalicylic acid reagent (DNS): Add 6.3 g DNS and 262 mL of 2 mol / L NaOH solution to 500 mL of hot aqueous solution containing 182 g of potassium sodium tartrate. Then add 5 g of redistilled phenol and 5 g of sodium bisulfite, stir to dissolve, cool, and bring the volume to 1000 mL. The solution is yellow and should be stored in a brown bottle.

[0050] 1 mg / mL glucose standard solution: Accurately weigh 1 g of analytical grade anhydrous glucose that has been dried to constant weight at 80℃, place it in a beaker, add a small amount of water to dissolve it, then add 5 mL of concentrated hydrochloric acid (to prevent microbial growth), and dilute to 1000 ml with distilled water. Mix well and store in a refrigerator at 4℃ for later use.

[0051] method: 1. Construct a glucose standard curve Take 6 test tubes and number them. Add 1 mg / mL glucose standard solution, distilled water, and 3,5-dinitrosalicylic acid (DNS) reagent to each tube according to the table. Mix all tubes thoroughly, zero the test tube using tube 0, and measure the absorbance of tubes 1-5 at 540 nm. Plot the absorbance in milligrams of glucose on the x-axis. 540 Use the vertical axis to plot the standard curve.

[0052] Table 3 Glucose Standard Curve

[0053] 2. Determination of reducing sugars in yam cake Set A: Control (no acidic substances added), B: Single acid (malic acid + citric acid), C: Compound acid (malic acid, citric acid, hawthorn pulp and plum juice), with the pH of each group controlled in the range of 6.2 to 6.8.

[0054] Each group contained salivary enzymes and different groups of yam cakes. After reacting at 37°C for 10 minutes, 1.0 mL of the reacted solution was taken into a test tube, 2.0 mL of DNS reagent was added, and the mixture was boiled in water for 2 minutes. After cooling, the volume was increased to 15 mL with water, and the absorbance was measured at 540 nm. The glucose mg / mL value was determined from the standard curve, and the sugar content in the sample was calculated and the enzyme activity was converted.

[0055] Table 4. Salivary amylase activity and relative activity The results showed that, under the conditions of 37 °C and 10 min, the compound acid group (C) exhibited the strongest synergistic activation of salivary amylase, significantly higher than that of the control group. This indicates that the compound acid system (C) can effectively enhance salivary amylase activity.

[0056] It will be understood by those skilled in the art that, unless otherwise defined, all terms used herein (including technical and scientific terms) have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. It should also be understood that terms such as those defined in general dictionaries should be understood to have the same meaning as in the context of the prior art, and should not be interpreted in an idealized or overly formal sense unless specifically defined as herein.

[0057] It should be understood that the above detailed description of the technical solutions of the present invention with reference to preferred embodiments is illustrative and not restrictive. Those skilled in the art can modify the technical solutions described in the embodiments or make equivalent substitutions for some of the technical features based on reading this specification; however, these modifications or substitutions do not cause the essence of the corresponding technical solutions to depart from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A yam cake with a complex acidic system synergistically activated by salivary amylase, characterized in that, The ingredients include yam, konjac flour or oligosaccharides, sweeteners, gelling agents, malic acid, citric acid, hawthorn, dried plums and water.

2. The yam cake according to claim 1, characterized in that, 80-100 parts yam, 0.2-0.8 parts konjac powder or oligosaccharide, 0.1-0.6 parts gelling agent, 0.02-0.1 parts malic acid, 0.1-0.2 parts citric acid, 2-8 parts hawthorn, and 2-8 parts dried plum.

3. The yam cake according to claim 1, characterized in that, Yam cake maintains a slightly acidic pH in the oral cavity, pH 6.2–6.8; further, pH 6.2–6.

5.

4. The yam cake according to claim 1, characterized in that, Gel agents include one or more of agar, pectin, and carrageenan.

5. The yam cake according to claim 1, characterized in that, Yam is in the form of yam pulp or yam powder; and / or hawthorn is in the form of hawthorn pulp; and / or dried plum is in the form of dried plum juice.

6. A method for preparing yam cake with a complex acidic system synergistically activated by salivary amylase, characterized in that, The ingredients include yam, konjac flour or oligosaccharides, sweeteners, gelling agents, malic acid, citric acid, hawthorn, plum juice, and water; The preparation steps include:

1. Raw material pretreatment: Thoroughly mix yam powder, konjac powder or oligosaccharides, sweeteners and gelling agents; 2. Acid preparation: Malic acid and citric acid are pre-dissolved, and hawthorn pulp and plum juice are taken to adjust the pH of the liquid to 6.2±0.2; 3. Gelatinization: Mix the acid solution with the dry powder, heat and stir to promote gel formation; 4. Filling and Cooling: The hot material is poured into the mold and allowed to cool and solidify.

5. Demolding and Packaging: After natural cooling or refrigeration, demold and package to obtain the finished product.

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