The Quality and Flavor Changes of Different Soymilk and Milk Mixtures Fermented Products during Storage

Abstract

This study explored the effects of two mixed fermentation methods: one was fermenting a soymilk and milk mixture by a lactic acid bacteria fermenting agent at 0.1 g/kg and 42 °C until the acidity was 70 °T, which was set as the MFSM method, and the other was fermenting milk alone by lactic acid bacteria at 42 °C for 12 h, placing it in a 4 °C refrigerator after acidification for 24 h and then mixing it with soymilk at a 1.5:1 ratio and storing the mixture at 4 °C, which was set as the SMFSM method. The quality and flavor of the soymilk and milk mixture products were investigated on the 0th, 15th and 30th days during storage. The changes in acidity, pH, number of viable bacteria, viscosity, water-holding capacity, texture, rheological properties, sensory quality and volatile flavors were determined. The results showed that compared with the fermented soymilk and milk mixtures under the MFSM method, the samples of fermented soymilk and milk mixtures under the SMFSM method showed a significant slowdown of acidification during storage, so that the sensory quality of the products was almost unaffected by acidity on the 30th day of storage. Furthermore, the number of viable bacteria was greater than 7 log cfu/mL. The water holding capacity did not change significantly until the 30th day. There was also no whey precipitation, indicating good stability. The samples in SMFSM mode had higher aromatic contents and beans during storage than the fermented soymilk and milk mixtures in MFSM mode. The rich variety of volatile flavors and the presence of acetoin, 2-heptanone, and (E,E)-3,5-octadien-2-one throughout the storage period allowed the samples to maintain a good sensory flavor during storage.

Determination of Nutritional Value, Antioxidant Activities, Microbiological and Sensory Properties of Almond, Soy and Oat Based Fermented Beverages

“…A temperature of 4°C during the storage phase causes an increase in the metabolism of LAB and causes high protein hydrolysis. With this mechanism, LABs cause the production of lactic acid, leading to acidi cation of milk contents [15,26]. In this study, the increase in acidity level of fermented soy and cow milk beverage as storage time increases can be explained by this mechanism.…”

“…All studies were designed differently from each other and the microbiological analyzes of the studies and the viability of probiotic microorganisms; adding microbial growth-promoting components such as FOS, galactooligosaccharide (GOS), inulin, glucose, sucrose, etc. to the medium during the fermentation stage; Using different storage temperatures such as refrigerator temperature (4°C and around) or freezing (-80°C and around) during the storage stage, storage period, direct procurement of milk components to be used before the fermentation process from raw materials through production or commercially, before the fermentation process applied pasteurization stage and temperature degree and duration, single or multiple combination of bacteria used in the fermentation process, differences in the bacteria used in the fermentation process, different log number strains of the bacteria used in the fermentation process even if they are the same brand, high oxidation-reduction potential, high acidity, low temperature, substrate Many factors can be effective, such as limitation and/or formation of starter culture metabolites (such as hydrogen peroxide and lactic acid), and the use of different counting methods, direct or indirect, in the counting method of microorganisms [8][9][10][11][12][13][14][15]. It is thought that the low number of B. lactis in this study may be due to the suppression of B. lactis growth by other bacterial strains.…”

Alternative Fermented Soy-Based Beverage: Impact of Inulin on the Growth of Probiotic Strains and Starter Culture

“…Adjustments to the sensory attributes of a food product can ensure that it will meet consumer and market demands; in addition, post-acidification studies can generate useful information for the development of food products with a balance of flavors, odors, and increased shelf life. This is an area of great relevance to the food sciences, as its findings have a direct impact on the nutritional value and health implications of fermented beverages [36][37][38][39]. By adjusting acidity levels after fermentation, for instance, scientists can enhance the availability of nutrients (minerals and vitamins), as well as modulate the growth and increase the survival rate of beneficial probiotics present in the beverage.…”