A Novel Approach to the Use of Xanthan Gum: Evaluation of Probiotic Promoter, Postbiotic Formation and Techno-Functional Effect.

In the present study, the effect of xanthan gum was evaluated on the metabolic activity and survival of two probiotic strains, namely B. lactis and L. casei using in vitro assay and skim milk model system. In vitro assay was carried out identifying by pH, optical cell density (OD), and formation of postbiotics (lactic, acetic, propionic, and butyric acids) in different basal media including glucose, inulin, and xanthan gum as carbon source. The highest pH values were recorded for control (without carbon source) and media with xanthan gum, whereas the media with glucose and xanthan gum had the highest OD values. In comparison to strains, B. lactis had higher pH and lower OD values than L. casei. It was found that xanthan gum supported the formation of postbiotics as a result of bacterial fermentation. In the skim milk model system, xanthan gum did not negatively affect probiotic viability, and the counts of both strains were above the required level for health benefits (8 log cfu g-1) after 28-day storage. The use of xanthan gum in skim milk matrix positively affected techno-functional properties such as syneresis, color, and textural parameters of samples.

Bioaccessibility and antioxidant capacity of kefir-based smoothies fortified with kale and spinach after in vitro gastrointestinal digestion.

The kefir-based smoothies with kale and spinach were designed as a ready-to-drink and innovative functional snack. Microbiological, physicochemical, as well as pre- and postgastrointestinal total antioxidant capacity (TAC; CUPRAC, DPPH, and FRAP) analyses were conducted. It was determined that the kefir-based smoothies with vegetables had higher ash, carbohydrate, and dietary fiber values. Fructose and glucose contents of smoothy with kale were high, while smoothy with spinach included high sucrose and maltose. The microbiology results revealed that kefir-based vegetable smoothies had minimum Lactobacillaceae viability (>log 7 cfu g-1) for the required functional effect after 14-day storage. Moreover, the addition of kale significantly increased (p < .01) the level of initial TAC (CUPRAC, DPPH, and FRAP) and total phenolic content (TPC) values. After in vitro gastric digestion analysis, smoothie with spinach demonstrated higher TAC and TPC values and the control sample had higher TAC and TPC values compared with a predigestion step. It was found that in vitro intestinal DPPH values were higher for the sample with spinach samples, while the sample with kale had the highest FRAP values. It was also found that the bioaccessibility indexes of plain kefir were determined to be the highest in both in vitro gastric and intestinal procedures. The present study provided novel insights into the in vitro digestion properties of kefir fortified with vegetables. Nevertheless, further studies are needed to identify the functional properties of the milk and plant matrices mixture using in vitro and in vivo trials.

Comparison of the targeted metabolomics and nutritional quality indices of the probiotic cheese enriched with microalgae.

The objective of this study is to evaluate the influence of mixed L. acidophilus LA-5 and enrichment with microalgae (C. vulgaris and A. platensis) on metabolomic formation in a brined cheese matrix. Microbiological, compositional, and metabolomic characterization were investigated during the ripening. It was found that the nutritional quality indices of the samples were based on amino acid and fatty acid characterization. Fifty-six metabolomics including fatty acids, amino acids, organic acids, minerals, and vitamins were detected using the HPLC-DAD, GC-MS, and ICP-OES-based methods. The results indicated that the enrichment with probiotic strain and microalgae led to an increase in the nutritional quality indices such as EAAI, NI, BV, MUFA/SFA, h/H, and DFA. The chemometric analysis (e.g. HCA and PCA) presented the variance between the cheese samples based on their attributes. The identification of cheese metabolomics throughout the ripening could be used for a better understanding of the functional ingredients-cheese matrix relationships and as a directive approach for novel dairy products in other metabolomic-related studies.

Optimization of formulation and process conditions of chestnut-based functional beverage using response surface methodology.

Response surface methodology was used to optimize the chestnut beverage production under the effect of the independent variables including dilution rate (x 1 ), dilution temperature (x 2 ), pasteurization time (x 3 ) and pasteurization temperature (x 4 ). The experiments were based on a central composite design with linear and quadratic models employed to study the combined effects of four independent variables. The responses were selected with functional properties such as antioxidative attributes and total phenolic content. The optimal conditions (x 1 , x 2 , x 3 and x 4 ) determined for development of chestnut based functional beverage were a dilution rate of 25.19 g/100 mL, a dilution temperature of 37.562 °C, a pasteurization time of 24.996 min. and a pasteurization temperature of 84.433 °C. After comparing the predicted and experimental results, the multi-response surface methodology was more stable with a good correlation for a functional chestnut beverage.

Effect of Cordyceps militaris on formation of short-chain fatty acids as postbiotic metabolites.

The aim of the current study was to determine the growth-promoting-effect of Cordyceps militaris, known as a medicinal mushroom, on Lactobacillus casei and Lactobacillus acidophilus. To evaluate the best growth-promoting activity of the test substrates including glucose, inulin, and at different concentrations of C. militaris (0.5%, 1%, and 2%), the cell counts, optical density (OD), prebiotic activity scores, and postbiotics (lactic, acetic, butyric, and propionic acids) were determined. The highest cell count was found for L. casei in media containing 0.5% C. militaris and for L. acidophilus in media containing 1% C. militaris. In the case of both strains, the OD values of the medium with C. militaris (1%) and (2%) increased similar to those of glucose. The prebiotic activity scores for both strains were positive. The concentration of lactic acid ranged from 0.56 to 8.07 g L-1 for L. casei and 0.82 to 5.38 g L-1 for L. acidophilus. Moreover, propionic acid was the highest among short-chain fatty acids (SCFAs) produced by both strains. According to the results of the present study, the tested Lactobacillus species can utilize C. militaris as carbon source and is able to form postbiotics in the media.

Evaluation of instrumental and sensory measurements using multivariate analysis in probiotic yogurt enriched with almond milk.

Highlights: Consumers demand the purchase of fortified dairy products.Instrumental (color, texture) and sensorial attributes are critical tests for novel food.Almond milk has high nutritional value with unique textural and sensorial properties.Almond milk is an innovative and attractive additive in probiotic yogurt. Abstract: In this study, the effect of almond milk addition on color, texture and sensory attributes of probiotic yogurt was investigated. The data generated in combination with instrumental (color and texture parameters) and sensory measurements was analysed statistically to describe a product's attributes scientifically. Statistical analysis illustrated that almond milk rate and storage time had a significant (P < 0.05) effect on the color and textural parameters of yogurt. Compared with the sensorial parameters, generally there were statistically significant differences among samples, whereas insignificant effect was determined among storage days. The results of descriptive statistics (Principle Component and Hierarchical Cluster Analysis) indicated that the relationships among the analysed attributes were determined. In addition, statistical data has demonstrated that almond milk may be used as a novel and functional ingredient in both industrial and research areas for development, innovation, quality, and safety of dairy products.

Short-chain fatty acids production by Bifidobacterium species in the presence of salep

BACKGROUND: Salep is obtained by grinding dried orchid tubers and used as a valuable ingredient in the food industry. Because of the glucomannan content of salep, it is thought to have prebiotic potential. However, there is little information in studies concerning the fermentation characteristics and potential prebiotic properties of salep. The objective of this study was to investigate the effect of salep on bifidobacterial growth by measuring the highest optical density (OD), calculating the specific growth rates, and determining the production of lactic acid and short-chain fatty acids (acetic, propionic, and butyric acid) as a result of bacterial fermentation. RESULT: The OD and pH values obtained in this study showed that salep was utilized as a source of assimilable carbon and energy by the Bifidobacterium species (BS). All Bifidobacterium strains produced lactic, acetic, propionic, and butyric acid, indicating that salep is readily fermented by these bacteria. Salep at 1% (w/v) showed a similar effect on bifidobacterial growth as that promoted by 1% (w/v) glucose used as a traditional carbon source. CONCLUSIONS: Bifidobacterium species can develop in media containing salep as well as in glucose and exhibit the potential to be used as new sources of prebiotics.

Comparison of antioxidant capacity of cow and ewe milk kefirs.

This research aimed to evaluate the effects of using either grain or commercial starter culture on the antioxidative capacity of cow and ewe milk kefirs. The antioxidant capacity of kefir samples during fermentation and 21 d of storage was assessed by using 3 assays: 2,2'-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS) radical cation decolorization; 2,2-diphenyl-1-picrylhydrazyl (DPPH•) radical scavenging activity assay; and Fe+3-reducing power (ferric reducing antioxidant power assay, FRAP). Vitamin E and ß-carotene contents were also quantified. All kefir samples exhibited varying values for DPPH, ABTS, and FRAP assays depending on the starter culture and milk type. Vitamin E and ß-carotene contents were similar in all kefir samples during storage. The results of this study suggest that milk type (cow or ewe) and culture type (kefir grains or commercial starter) were the significant parameters for the antioxidative activity of kefir.