Lactic acid bacteria viability in different refrigerated food matrices: a systematic review and Meta‑analysis

The aim of this systematic review and meta-analysis was to determine which variables affect the viability of lactic acid bacteria (LAB) added to different types of refrigerated foods during the first 28 days. Scopus, ScienceDirect, PubMed and Cochrane Central Register of Reviews databases were searched from 1997 to April 2022. A total of 278 studies, which showed randomized and controlled experiments published in peer reviewed journals, were included. The viability of LAB in different moments during the storage process was synthesized as mean point estimate (MPE) via random-effects meta-analyses and the effect of multiple factors on the LAB´s viability was evaluated by multiple meta-regression. The meta-analysis showed that the decrease in LAB viability will be more abrupt the greater the initial dose. The physical structure of food may influence bacterial viability. Fruit was the type of product that most quickly lost viability. Co-culture of two or more species did not affect viability. Preservation methods had an unfavorable effect and prebiotics had a beneficial effect on bacterial viability. Viability was genus dependent. The data obtained in this study provide an overview of the factors to be taken into account for the design of new foods.

Ready to Use Therapeutical Beverages: Focus on Functional Beverages Containing Probiotics, Prebiotics and Synbiotics

The growing global interest in functional foods containing nutrients capable of adding possible beneficial health effects is rapidly increasing both interest and consumer demand. In particular, functionalized beverages for their potential positive effect on health e.g., decreasing cholesterol level, lowering sugar, high fiber content, ability to enhance the immune system, and help digestion, have recently received special attention. Among the different beverages available on the market, probiotic dairy and non-dairy products have attracted much attention because of their affordable cost and their numerous therapeutic activities. Fermented milk and yogurt are currently worth €46 billion, with 77% of the market reported in Europe, North America, and Asia. Consumption of dairy beverages has some limitations due for example to lactose intolerance and allergy to milk proteins, thereby leading consumers to use non-dairy beverages such as fruit, grains, and vegetable juices to add probiotics to diet as well as driving the manufacturers to food matrices-based beverages containing probiotic cultures. The purpose of this review article is to evaluate the therapeutic performance and properties of dairy and non-dairy beverages in terms of probiotic, prebiotic, and synbiotic activities.

In Vitro Modulation of Fecal Microflora Growth Using Fermented “Pisang Mas” Banana and Red Guava Juices

Probiotic drink like yoghurt from dairy milk is one of the most popular functional food. However, some people are not able to consume dairy milk due to lactose intolerance. Thus, a substitute substrate such as fruit juice, is needed. It refers to prebiotic compounds that are found in some of fruits like banana and guava. The aim of this research was to determine the effect of fermented banana and guava juices on the viability of fecal microflora. The juices were made from banana or red guava fermented by Lactobacillus casei (15% v/v). In vitro test was conducted using indigenous human fecal bacteria (1% w/v). The viability of enteropathogens, lactic acid bacteria (LAB), and total microbes was determined by enumeration as well as the prebiotic index of the fermented juices. The in vitro test results showed that both fermented juices could elevate the total microbes and LAB as compared to control sample. The viability of the total microbes and LAB increased by 2.16 log CFU/mL and 2.90 log CFU/mL for fermented banana juice (FBJ), respectively. The same trend was also observed in fermented guava juice (FGJ) with an increase by 1.92 log CFU/mL for total microbes and 2.99 log CFU/mL for LAB. Interestingly, both fermented juice could decrease the population of most enteropathogens compared to control sample. FBJ could decrease the population of E. coli, Klebsiella sp. and Salmonella as low as 3.78, 3.32, and 1.37 log CFU/mL respectively. Meanwhile, FGJ could drop the number of E. coli (1.44 log CFU/mL), and Klebsiella sp. (1.29 log CFU/mL). Moreover, the prebiotic index for FBJ and FGJ were 2.57 and 2.16. In conclusion, both FBJ and FGJ were potential substrate for probiotic drink and had good effect for fecal microflora health.