Physiochemical properties and probiotic survivability of symbiotic oat-based beverage

Exploring the Role of Lactic Acid Bacteria Blends in Shaping the Volatile Composition of Fermented Dairy and Rice-Based Beverages: A Step towards Innovative Plant-Based Alternatives

Plant-based products are currently gaining consumers' attention due mainly to the interest in reducing the consumption of foods of animal origin. A comparison of two fermentative processes utilizing dairy milk and a rice beverage was conducted in the present study, using a commercial lactic acid bacteria strain combination (CH) and a selected mixture of lactic acid bacteria from yogurt (LLV). Cell viability and physicochemical characteristics (total soluble solids, pH, total acidity) were determined to describe the samples before and after fermentation, as well as the volatile composition (gas chromatography-mass spectrometry) and the sensory profile (Rate-All-That-Apply test). Results of the analyses showed significant differences among samples, with a clear effect of the raw material on the volatile profile and the sensory characterization, as well as a significant effect of the microbial combination used to ferment the matrices. In general, the selected LLV strains showed a greater effect on both matrices than the commercial combination. Dairy samples were characterized by a volatile profile represented by different chemical families (ketones, lactones, acids, etc.), which contributed to the common descriptive attributes of milk and yogurt (e.g., dairy, cheese). In contrast, rice beverages were mainly characterized by the presence of aldehydes and alcohols (cereal, legume, nutty).

Nutritional and Phytochemical Composition and Associated Health Benefits of Oat (Avena sativa) Grains and Oat-Based Fermented Food Products

Oats (Avena sativa L.) are a popular functional cereal grain due to their numerous health benefits. This review article summarized the information on the chemical composition and phytonutrients of oats grown in different countries. It also reviewed recently developed fermented oat products to highlight their potential for human health. Oats have an interesting nutritional profile that includes high-quality protein, unsaturated fats, soluble fiber, polyphenolic compounds, and micronutrients. Oat grain has a unique protein composition, with globulins serving as the primary storage protein, in contrast to other cereals, where prolamins are the main storage proteins. Oats have the highest fat content of any cereal, with low saturated fatty acids and high essential unsaturated fatty acid content, which can help reduce the risk of cardiovascular diseases. Oats are a good source of soluble dietary fiber, particularly β-glucan, which has outstanding functional properties and is extremely important in human nutrition. β-Glucan has been shown to lower blood cholesterol and glucose absorption in the intestine, thereby preventing diseases such as cardiovascular injury, dyslipidemia, hypertension, inflammatory state, and type 2 diabetes. Oats also contain high concentration of antioxidant compounds. Avenanthramides, which are unique to oats, are powerful antioxidants with high antioxidative activity in humans. Recognizing the nutritional benefits of oats, oat-based fermented food products are gaining popularity as functional foods with high probiotic potential.

Effect of food matrix and fermentation on angiotensin-converting enzyme inhibitory activity and β-glucan release after in vitro digestion in oat-based products

The aim of this study was to determine the effects of fermentation and food matrix on the ACE inhibitory activities of the peptides obtained after in vitro gastrointestinal digestion, protein profiles (SDS-PAGE) and β-glucan amounts of oat products. Furthermore, the physicochemical and microbiological properties of fermented oat drinks and oat yogurt-like product obtained from oat fermentation were evaluated. Oat grains were mixed with a certain ratio of water 1:3 w/v (oat:water, yogurt consistency) and 1:5 w/v (oat:water, drink consistency), and this mixture was fermented with yogurt culture and probiotic Lactobacillus plantarum and fermented drinks and yogurt were produced. The results indicated that the fermented oat drink and the oat yogurt-like product had L. plantarum viability over 10⁷ cfu/g. After the in vitro gastrointestinal digestion of the samples, the hydrolysis levels ranged from 57.70 % to 82.06 %.The hydrolysis level of the samples with fermented-drink consistency was significantly higher than the samples with yogurt consistency (p < 0.05).The SDS-PAGE profiles of the non-digested samples showed that the bands had molecular weights of 12-15 kDa and around 35 kDa. Bands whose molecular weights were around 35 kDA disappeared after gastric digestion. ACE inhibitory activities of the fractions composed of molecular weights of 2 kDa and 2-5 kDa obtained after in vitro gastrointestinal digestion of the oat samples were in the range of 46.93-65.91 %. The effect of fermentation on the ACE inhibitory activities of the peptide mixture with molecular weights between 2 and 5 kDa was not statistically significant, however, fermentation caused an increase in the ACE inhibitory activities of the peptide mixture with a molecular weight<2 kDa (p < 0.05). The β-glucan amounts of fermented and non-fermented oat products were in the range of 0.57-1.28 %. The β-glucan amounts detected after gastric digestion decreased considerably and β-glucan could not be detected in the supernatant after gastrointestinal digestion. This indicated that β-glucan did not solubilize in the supernatant (bioaccessible) and remained in the pellet. In conclusion, fermentation is a valuable process for releasing peptides with moderately high ACE inhibitory effects from the parent oat proteins.

Evidence and Updates on non-dairy synbiotic beverage development

BACKGROUND

With the increase in cases of intolerance and allergies to milk protein, new food possibilities have been studied as an alternative to dairy drinks in order to meet the needs of this population, such as, non-dairy synbiotic drinks.

OBJECTIVE

The aim of this study was to carry out an integrative literature review on the main types of non-dairy synbiotic beverages, in order to investigate the probiotics and prebiotics added to them. Besides, we also looked into the characteristics of the substrates and fermentation conditions (temperature, time and pH), to assess the influences on bacterial viability, consumer acceptance, conservation and antimicrobial action.

METHODS

We conducted an integrative review of articles published on Pubmed, Web of Science, Scielo, Scopus and Capes journal in the last five years, using the following terms: symbiotic drink, symbiotic beverage, synbiotic drink, synbiotic beverage, bebida simbiótica, not kombucha, which after reading, resulted in the inclusion of 28 articles.

RESULTS

As expected, the main probiotics used were from the genera Lactobacillus and Bifidobacterium, and the prebiotics were inulin and fructooligosaccharide. It is noteworthy that all analyzed beverages were in fact probiotics since they obtained values above the minimum viability of 6 log CFU / mL, consequently, they can bring benefits to consumers.

CONCLUSION

Thus, beyond fruits and vegetables being rich sources of nutrients, they also enable the development of synbiotic drinks delivered from their substrates, being an alternative for the public with restrictions to milk.

Influence of processing and packaging conditions on probiotic survivability rate, physico-chemical and sensory characteristics of low calorie synbiotic milk beverage

The work presented in this research communication was carried out to prepare low calorie synbiotic milk beverage by optimizing water and sugar level and to investigate the effect on its storage ability of different packaging materials (polypropylene, high impact polystyrene, high-density polyethylene and glass). Addition of both water and sugar significantly (P < 0.05) affected the viscosity, probiotic count and sensory properties. Based on the findings, 40% water and 8% sugar level were optimized for the preparation of the beverage. Apparent viscosity and acidity increased whilst pH and probiotic counts declined during storage, irrespective of packaging materials. The prepared beverage remained most acceptable at refrigeration temperature up to a period of 15 and 12 d when packaged in glass and high impact polystyrene, respectively. Furthermore, it retained a minimum recommended level of probiotic (7 log cfu/ml) during storage for 15 d at 4 °C.

Emmer-Based Beverage Fortified with Fruit Juices

Nowadays, there is a growing consumer demand for non-dairy functional foods due to several health issues related to milk and dairy consumption and increasing vegetarianism. Following that trend, in the present study emmer-based beverages were developed after flour gelatinization, fortification with fruit juices (blueberry, aronia, and grape) and fermentation with the potential probiotic strain Lactiplantibacillus plantarum 2035. The produced beverages were subjected to a 4-week storage at 4 °C. The addition of juices significantly affected the physicochemical characteristics of the beverages, while resulting in increased red color. Total phenolic content (22.3–31.9 mg gallic acid equivalents 100 g−1) and antioxidant activity (94–136 μmol Trolox equivalents 100 g−1) were significantly higher in the case of aronia juice followed by blueberry and grape juice. All beverages showed high values of apparent viscosity and water-holding capacity. Lactiplantibacillus plantarum 2035 retained high viable counts during storage especially in beverages with fruit juices (>108 cells g−1 up to 21st day) revealing a positive effect of the juices. The obtained results show that emmer-based beverages fortified with fruit juices (aronia, blueberry, and grape) have a great potential as carriers of probiotics, prebiotics and other functional compounds and may be served as an ideal alternative to dairy products.

Production and Characterization of a Novel Gluten-Free Fermented Beverage Based on Sprouted Oat Flour

This study investigates the use of sprouted oat flour as a substrate to develop a novel gluten-free beverage by fermentation with a probiotic (Lactobacillus plantarum WCFS1) starter culture. Physicochemical, microbiological, nutritional and sensory properties of sprouted oat fermented beverage (SOFB) were characterized. After fermentation for 4 h, SOFB exhibited an acidity of 0.42 g lactic acid/100 mL, contents of lactic and acetic acids of 1.6 and 0.09 g/L, respectively, and high viable counts of probiotic starter culture (8.9 Log CFU/mL). Furthermore, SOFB was a good source of protein (1.7 g/100 mL), β-glucan (79 mg/100 mL), thiamine (676 μg/100 mL), riboflavin (28.1 μg/100 mL) and phenolic compounds (61.4 mg GAE/100 mL), and had a high antioxidant potential (164.3 mg TE/100 mL). Spoilage and pathogenic microorganisms were not detected in SOFB. The sensory attributes evaluated received scores higher than 6 in a 9-point hedonic scale, indicating that SOFB was well accepted by panelists. Storage of SOFB at 4 °C for 20 days maintained L. plantarum viability and a good microbial quality and did not substantially affect β-glucan content. SOFB fulfils current consumer demands regarding natural and wholesome plant-based foods.

Non-Dairy Fermented Beverages as Potential Carriers to Ensure Probiotics, Prebiotics, and Bioactive Compounds Arrival to the Gut and Their Health Benefits

In alignment with Hippocrates' aphorisms "Let food be your medicine and medicine be your food" and "All diseases begin in the gut", recent studies have suggested that healthy diets should include fermented foods to temporally enhance live microorganisms in our gut. As a result, consumers are now demanding this type of food and fermented food has gained popularity. However, certain sectors of population, such as those allergic to milk proteins, lactose intolerant and strict vegetarians, cannot consume dairy products. Therefore, a need has arisen in order to offer consumers an alternative to fermented dairy products by exploring new non-dairy matrices as probiotics carriers. Accordingly, this review aims to explore the benefits of different fermented non-dairy beverages (legume, cereal, pseudocereal, fruit and vegetable), as potential carriers of bioactive compounds (generated during the fermentation process), prebiotics and different probiotic bacteria, providing protection to ensure that their viability is in the range of 106-107 CFU/mL at the consumption time, in order that they reach the intestine in high amounts and improve human health through modulation of the gut microbiome.

Fermented soymilk and soy and cow milk mixture, supplemented with orange peel fiber or Tremella flava fermented powder as prebiotics for high exopolysaccharide-producing Lactobacillus pentosus SLC 13

BACKGROUND

A high exopolysaccharide-producing Lactobacillus pentosus SLC 13 strain was isolated from mustard pickles and showed the characteristics of a probiotic. Orange peel fiber powder (OPFP) and Tremella flava fermented powder (TFP) were shown to be potential prebiotics for L. pentosus SLC 13. The present study aimed to further develop new symbiotic fermented lactic acid beverages using SLC 13 with different proportions of cow milk and soymilk as food substrates, as well as with OPFP or TFP as prebiotics.

RESULTS

Acidification rate (soymilk groups, 3.02-4.37 mU min^-1 ; soymilk/milk mixture groups, 1.33-2.84 mU min^-1 ) and fermentation time (soymilk groups, 7.09-9.25 h; soymilk/milk mixture groups, 12.51-27.34 h) indicated that soymilk represents a suitable substrate for SLC 13-mediated fermentation. Moreover, OPFP and TFP induced a higher exopolysaccharide production of SLC 13 and a higher water holding capacity of fermented beverages. Sensory evaluations suggested that soymilk groups fermented with 10 g kg^-1 OPFP (SF-1.0P) and that with 5 g kg^-1 TFP (SF-0.5T) and also soymilk/milk mixture groups fermented with 5 g kg^-1 OPFP (HSMF-0.5P) and that with 10 g kg^-1 TFP (HSMF-1.0T) represent potential fermented drinks. Additionally, SF-1.0P and SF-0.5T products could be preserved for at least 21 days at 4 °C, with high viable cell counts (> 8.8 log₁₀ CFU mL^-1 ) and water holding capacity.

CONCLUSION

In the present study, we developed SF-1.0P and SF-0.5T products as a new symbiotic fermented lactic acid beverages. However, in the future, consumer acceptability could be improved by properly regulating the ratio of sugar to acid or seasoning. © 2019 Society of Chemical Industry.