JP4872892B2 - Water separation inhibitor for overfermented yogurts and yogurts using the same - Google Patents

Description

  The present invention effectively prevents water separation of yogurts that have been over-fermented during storage after production, and maintains the mouthfeel of the yogurts inherently smooth and well-dissolved. And overfermented yogurts using the same.

  Yogurt is produced by fermenting milk such as milk by the action of lactic acid bacteria and yeast, and further adding sweeteners such as sugar, stabilizers and the like as necessary. Yogurt is prepared by filling the container with raw material mixed with raw milk, lactic acid bacteria, yeast, etc. due to the difference in production method, proceeding fermentation as it is to make fermented milk in the container (post-fermentation type), and the mixed raw material After fermenting in a tank or the like, it can be broadly divided into methods (pre-fermentation type) in which the produced fermented milk is filled in a container.

  Moreover, yogurt is roughly classified into solid yogurt (plain yogurt, hard yogurt), soft yogurt, drink yogurt, and frozen yogurt depending on the shape. Solid yogurt is produced by either a post-fermentation type that ferments after filling, or a pre-fermentation type method that adds agar or the like to fermented milk. Soft yogurt is obtained by stirring and smoothing fermented milk, drink yogurt is obtained by liquefying fermented milk, and frozen yogurt is obtained by freezing liquid fermented milk like ice cream. In the present invention, these various yogurts are collectively referred to as yogurts.

  Live bacteria-type yogurts that are not sterilized undergo fermentation while they are put on the market after production, resulting in a so-called over-fermentation state, and water separation (separation of whey) occurs over time. As a method for preventing this, stabilizers such as pectin derived from fruits such as agar, apple or citrus, gellan gum, carrageenan, gelatin, alginate and starch are used. For example, a yogurt containing a pectin, a calcium binding agent and a gelling agent and subjected to heat shock treatment (Patent Document 1), or a food using low gel strength agar, which is a yogurt using agar (Patent Document) 2) etc. have been proposed.

  However, it is difficult for all the stabilizers to completely prevent water separation, and the original smooth texture of yogurts is impaired. For example, when agar is blended, the texture of gel unique to agar is lost and creaminess is lost. On the other hand, when blended with fruit-derived pectin, the viscosity characteristic of pectin appears, resulting in poor throat penetration and poor milk flavor. There is a problem of becoming.

  Examples of pectin derived from potatoes include pectin (patent document 3) characterized by hot water extraction from potato starch candy under mildly acidic conditions, pectin extracted from sweet potato starch candy using a chelating agent (patent Document 4) and the like are disclosed. The pectin of Patent Document 3 describes a function as a stabilizer for acidic protein foods, particularly as a dispersion stabilizer for protein particles of protein beverages in the pH range above the isoelectric point of milk protein. A function as a gelling agent for gelled foods has been proposed, and the effect of yogurt on water separation, particularly on the water separation effect on hyperfermented yogurts in the pH range below the isoelectric point of protein has not been studied so far. .

Japanese Patent Laid-Open No. 9-218633 JP-A-6-038691 Japanese Patent No. 3519552 WO2006 / 126502

  An object of the present invention is to provide a water separation prevention agent for overfermented yogurts that is highly effective in preventing water separation and that retains the original smooth and mouth-feeling texture of yogurts.

  As a result of diligent research to solve the above problems, the present inventors have promoted stabilization of acidic protein beverages in the pH range above the isoelectric point of protein when pectin extracted from potatoes is added to yogurts. Surprisingly, these pectin are effective in preventing water separation of overfermented yogurts with a pH lower than the isoelectric point of the protein, and produce yogurts with the original smooth and mouth-feeling texture. I found out that I can do it. The present invention has been completed based on such findings.

That is, the present invention is (1) an anti-water separation agent for overfermented yogurts containing pectin extracted from potatoes as an active ingredient.
(2) The water separation inhibitor according to (1), wherein pectin is extracted from potato.
(3) The water separation inhibitor according to (1), wherein the overfermented yogurts have a pH of less than 4.5.
(4) An overfermented yogurt characterized by containing the water separation inhibitor according to (1) at 0.007% by weight or more and less than 1.5% by weight.
It is.

  According to the present invention, it is possible to provide yogurts with reduced water separation while maintaining the original smooth texture of yogurts regardless of the overfermented state.

  The potato pectin used in the present invention refers to acidic polysaccharides obtained by various extraction methods from the cell walls of potatoes, preferably pectin extracted from sweet potato or potato, and most preferably pectin extracted from potato. Although the extraction method is not particularly specified, examples include weakly acidic conditions of 100 ° C. or higher, extraction using a chelating agent, and the like, and pectin obtained under these conditions is preferable. For example, the production method described in Patent Document 3 in which pectin is extracted with hot water at a temperature of 100 ° C. or higher under a weakly acidic condition of pH 3.8 to 5.3 from potato starch lees, or 75 ° C. or higher in the presence of a chelating agent from sweet potato starch lees And pectin obtained by the production method described in Patent Document 4 in which pectin is extracted with hot water.

  The yogurts used in the present invention are mainly raw materials such as milk, skim milk powder, whole milk powder, whole fat condensed condensed milk, skimmed condensed milk, animal milk such as goat, sheep, buffalo, and horse, or soy milk or separated soy protein solution. And a fermenter of the same kind as that of normal fermented milk, such as lactic acid bacteria and yeast, is prepared by fermentation using a starter. As described above, both post-fermentation type and pre-fermentation type are included, and solid yoghurt (plain yoghurt, hard yoghurt), soft yoghurt, drink yoghurt, and frozen yoghurt are included. The post-fermentation type is preferable when water separation is more effectively suppressed.

  Overfermented yogurts mean yogurts that have been placed in circulation after production and have undergone fermentation. As the index, the pH of yogurts can be used, and in the present application, yogurts having a pH of yogurts of less than pH 4.5, preferably pH 4.4 or less are defined as overfermented yogurts.

  The amount of potato pectin added to yogurt is not particularly limited, but for example 0.007 wt% or more and less than 1.5 wt%, preferably 0.02 wt% or more and less than 0.7 wt%, more preferably 0.07 wt% or more and less than 0.7 wt% It is. When the addition amount is less than 0.007% by weight, the effect of preventing water separation is weak, and when 1.5% by weight or more is added, the yogurt may cause aggregation.

  In the present invention, the potato pectin is added to the yogurts at the time of adding the potato pectin powder as it is to a raw material containing milk and water, or as an aqueous solution in which the potato pectin is dissolved in water. Also good. Post-fermentation type yogurts are fermented after sterilizing and heating raw material milk and cooling to fermentation temperature, inoculating lactic acid bacteria, filling the container, and then fermenting. The potato pectin functions in any process, but it is preferably added before sterilization and heating because of bacterial control and ease of dissolution. On the other hand, pre-fermented yogurts are filled in a container after the fermented milk is stirred and smoothed. The potato pectin functions in any process, but before fermentation, if it is before fermentation, before sterilization heating, if it is after fermentation, from stirring and crushing fermented milk until just before filling the container It is preferable to add between. Potato pectin is soluble in cold water and does not need to be dissolved in hot water like agar. Moreover, since it has a lower viscosity than fruit-derived pectin and changes in physical properties due to temperature are small, there is an advantage that it is easy to use when producing yogurts.

  The yogurts of the present invention are characterized by using the above-mentioned potato pectin, but as long as they do not affect the present invention, agar, fruit-derived pectin, water-soluble soybean polysaccharide, gum arabic, gelatin , Xanthan gum, guar gum, locust bean gum, gellan gum, tragacanth gum, tamarind gum, tara gum, karaya gum, curdlan, glucomannan, alginic acids (alginic acid, alginate), CMC, one or more of microcrystalline cellulose May be.

  The sweetener used for yogurt may be any known one, and specifically, sugar, honey, maple syrup, molasses, molasses, fructose, maltose, oligosaccharide, isomerized sugar, invert sugar , Sugar alcohol, sugar-bound starch syrup, trehalose, licorice extract, saccharin (sodium saccharin), aspartame, acesulfame potassium, sucralose, stevia extract, stevia powder, etc.

  Moreover, you may add vitamins, calcium, such as calcium lactate and calcium gluconate, minerals, such as iron, magnesium, phosphorus, potassium, etc. as needed.

  In addition, grape, peach, cherry, strawberry, blueberry, raspberry, pear, apple, mandarin, pineapple, melon, kiwi, aloe, carrot, pumpkin, radish, celery, parsley, tomato, sweet potato, potato, taro, mushroom, herb Juices such as fruits, or flesh and leaves can be made into small pieces and added to the yogurts of the present invention. In addition, eggs, fresh cream, matcha, nata de coco, nuts, chocolate, jelly, caramel, vanilla, cheese, bavaroa, coffee, etc. are added to the yogurt of the present invention to obtain a yogurt product with enhanced palatability I can do it.

  Hereinafter, the embodiments of the present invention will be described by way of examples. However, these are merely examples, and the spirit of the present invention is not limited by these examples. Note that. In the examples, both parts and% mean weight basis.

Example 1 Preparation of Potato Pectin Potato pectin was used as a pectin derived from root vegetables. The pectin was prepared by suspending 50 g of dried potato starch koji in 950 g of water, adjusting the pH to 4.5 with hydrochloric acid and heating at 110 ° C. for 90 minutes to extract crude pectin. After cooling, centrifugation (10,000 × g, 30 minutes) was performed to separate the pectin extract from the precipitate. To the obtained crude pectin solution, an amylase solution (AMG300L: novozymes) equivalent to 1% of starch contained in the crude pectin is added to decompose the starch at 60 ° C. for 3 hours, and in a boiling water bath, 10%. The enzyme was inactivated by heating for a minute. Ethanol was added to a final concentration of 50% to precipitate pectin, and this precipitate was washed with 80% ethanol to obtain purified potato pectin.
Example 2 Preparation of sweet potato pectin After suspending 50 g of dried sweet potato starch koji in 950 g of a 50 mM disodium hydrogen phosphate solution, the crude pectin was extracted by heating at 120 ° C. for 60 minutes. After cooling, centrifugation (10,000 × g, 30 minutes) was performed to separate the pectin extract from the precipitate. To the obtained crude pectin solution, an amylase solution (AMG300L: novozymes) equivalent to 1% of starch contained in the crude pectin is added to decompose the starch at 60 ° C. for 3 hours, and in a boiling water bath, 10%. The enzyme was inactivated by heating for a minute. Pectin was precipitated by adding ethanol to a final concentration of 50%, and this precipitate was washed with 3 times the amount of 80% ethanol (containing 1% hydrochloric acid). Further, three times the amount of 80% ethanol was added, adjusted to pH 6 with an aqueous sodium hydroxide solution, washed three times with 90% ethanol, and dried to obtain purified sweet potato pectin.

Example 3 Preparation of Yogurt Yogurt was prepared using the potato pectin prepared in Example 1 and the sweet potato pectin prepared in Example 2. For comparison, agar (trade name: Ina Agar SY-6, manufactured by Ina Food Industry Co., Ltd.), low gel strength agar (trade name: Ultra Agar AX-150L, manufactured by Ina Food Industry Co., Ltd.), fruit origin Pectin (trade name: GENU pectin LM-106AS-YA-J, manufactured by Sanki Co., Ltd.) was used.
In accordance with the formulation in Table 1, while stirring the milk, add skim milk powder, sugar and various polysaccharide aqueous solutions that can be expected to prevent water separation, add 97 parts with pure water, dissolve at 70 ° C for 10 minutes, and evaporate The water was corrected and homogenized at 150 kg / cm ^ 2 using a homogenizer. Next, after sterilizing by heating at 95 ° C. for 5 minutes, the mixture was cooled to 40 ° C., a starter was added, the vessel was filled, and fermented to pH 4.5 with a 40 ° C. incubator for 5 hours. Subsequently, after rapidly cooling to 20 ° C. in a constant temperature water bath, it was left in a refrigerator at 4 ° C. overnight to prepare yogurt. The pH of yogurt after standing overnight was 4.3.

(Table 1) Contains yogurt (non-fat milk solids 10%: milk fat 2.45%)

(Table 2) Effects of various stabilizers

  Whether the state of the yogurt body corresponds to “good”, “slightly aggregated”, or “not set (gelled)” was evaluated. In addition, regarding the presence of a separated water layer (water separation) on the yogurt surface, “+” indicates that water has been removed, “±” indicates that water is slightly separated, and “−” indicates that water is not separated. It was confirmed that the use of potato pectin and sweet potato pectin could prevent water separation compared to the case where no stabilizer was added. In addition, these were smooth and meltable, which is the original texture of yogurt. On the other hand, the agar and fruit-derived pectin, which is a comparative example, was able to prevent water separation in the same way as potato pectin, but the texture was heavy, the mouth melted poorly, and the original smoothness of yogurt was impaired.

Example 4 Optimum addition amount of potato pectin The addition amount of potato pectin prepared in Example 1 was changed from 0.005 to 3.0% by weight, and the addition amount of sweet potato pectin prepared in Example 2 was changed from 0.1 to 0.5% by weight. The effect of the present invention was examined. Preparation and evaluation of yogurt were performed in the same manner as in Example 3. The results are shown in Table 3.

(Table 3) Effects at each concentration

  When potato pectin was added in an amount of 0.05 to 0.5% by weight based on yogurt, water separation could be effectively prevented. Furthermore, the original smooth texture of yogurt was maintained, which was preferable. When the addition amount was 1.0% by weight, there was a slight tendency to agglomerate after fermentation, and when the addition amount was 2.0% by weight or more, the texture was rough. In addition, yogurt prepared by adding sweet potato pectin had a tendency to agglomerate slightly when added at 0.5% by weight, and although water separation could be prevented, the texture of yogurt tended to be somewhat rough. From these results, it was found that potato is particularly preferable among potatoes as a water separation preventing agent that does not impair the original texture of yogurt.

Example 5 Stability of yogurt 0.1% by weight of potato pectin prepared in Example 1 was added, and fermentation was performed until the pH reached 3.8, 4.0, 4.2, 4.4, 4.6, and the effect of the present invention was examined. Preparation and evaluation of yogurt were performed in the same manner as in Example 3. The results are shown in Table 4. The pH of yogurt after standing overnight was 3.7, 3.9, 4.1, 4.2, and 4.4, respectively.

(Table 4) Effects at each pH

  The yogurt after storage had an effect of preventing water separation within the range of 3.7 to 4.4, and the texture was smooth. After the yogurt was produced, it was confirmed that water separation could be prevented by adding potato pectin even when the fermentation progressed over time during distribution and the pH fell below the isoelectric point.

Claims (4)

An anti-wetting agent for overfermented yogurts with fermentation progressing and a pH of less than 4.5 , comprising pectin extracted from potatoes as an active ingredient. The water separation inhibitor according to claim 1, wherein pectin is extracted from potato. The water separation inhibitor according to claim 1, wherein pectin is extracted from sweet potato. An overfermented yogurt comprising the water separation inhibitor according to claim 1 in an amount of 0.007 wt% or more and less than 1.5 wt%.