Fermentation Potential of L actobacillus rhamnosus and L actobacillus acidophilus in Date Syrup to Develop a Functional Fermented Beverage: A Comparative Study

Development, characterisation and sensory qualities of probiotic beverage from provitamin A cassava (Manihot esculenta crantz) starch hydrolysate with free and encapsulated Lacticaseibacillus rhamnosus GG

The suitability of hydrolysate (ready-to-drink beverage) from provitamin A cassava (PAC) starch as a carrier for probiotic Lacticaseibacillus rhamnosus GG (LGG) was evaluated. PAC starch was hydrolysed by α-amylase and glucoamylase. The PAC starch hydrolysate, fermented with free or alginate-encapsulated LGG (at 37 °C, 48 hours), was evaluated for lactic acid production (using high-performance liquid chromatography), descriptive sensory attributes on a 9-point hedonic scale and total viable counts of LGG cells in PAC hydrolysate during fermentation and storage (4 °C, 60 days). Analysis of variance was conducted and statistical significance was accepted at p< 0.05.Lactic acid was significantly (p< 0.05) produced in PAC hydrolysate with LGG during fermentation (1980-5480 mg/L), and storage (up to 13676.90 mg/L). LGG maintained significant viability in PAC hydrolysate after fermentation (9 log CFU/mL) and 60 days of storage (5 log CFU/mL). LGG-fermented PAC hydrolysate showed significant overall acceptability of 49.56-56.33% in sensory attributes.PAC hydrolysate with LGG showed significant acceptability and offered adequate support for the metabolism of LGG, evidenced by a significant production of lactic acid during fermentation and refrigerated (4 °C) storage, with adequate viability. Therefore, PAC is a suitable non-dairy carrier for probiotic LGG.

The Sustainability of Sweet Potato Residues from Starch Processing By-Products: Preparation with Lacticaseibacillus rhamnosus and Pediococcus pentosaceus, Characterization, and Application

The effects of Lacticaseibacillus rhamnosus and Pediococcus pentosaceus on the nutritional-functional composition, structure, in vitro saliva-gastrointestinal digestion, and colonic fermentation behaviors of fermented sweet potato residues (FSPR) were investigated. The FSPR was obtained under the condition of a solid-to-liquid ratio of 1/10, inoculation quantity of 1.5%, mixed bacteria ratio 1:1, fermentation time of 48 h, and fermentation temperature of 37 °C. The FSPR showed higher contents of soluble dietary fiber (15.02 g/100 g), total polyphenols content (95.74 mg/100 g), lactic acid (58.01 mg/g), acetic acid (1.66 mg/g), volatile acids (34.26%), and antioxidant activities. As exhibited by FTIR and SEM, the higher peak intensity at 1741 cm^-1 and looser structure were observed in FSPR. Further, the FSPR group at colonic fermentation time of 48 h showed higher content of acetic acid (1366.88 µg/mL), propionic acid (40.98 µg/mL), and butyric acid (22.71 µg/mL), which were the metabolites produced by gut microbiota using dietary fiber. Meanwhile, the abundance of Bifidobacterium and Lacticaseibacillus in the FSPR group was also improved. These results indicated that FSPR potentially developed functional foods that contributed to colonic health.

Date Fruits as Raw Material for Vinegar and Non-Alcoholic Fermented Beverages

Currently, foods and beverages with healthy and functional properties, especially those that claim to prevent chronic diseases, are receiving more and more interest. As a result, numerous foods and beverages have been launched onto the market. Among the products with enhanced properties, vinegar and fermented beverages have a high potential for growth. Date palm fruits are a versatile raw material rich in sugars, dietary fibers, minerals, vitamins, and phenolic compounds; thus, they are widely used for food production, including date juice, jelly, butter, and fermented beverages, such as wine and vinegar. Furthermore, their composition makes them suitable for the formulation of functional foods and beverages. Microbial transformations of date juice include alcoholic fermentation for producing wine as an end-product, or as a substrate for acetic fermentation. Lactic fermentation is also documented for transforming date juice and syrup. However, in terms of acetic acid bacteria, little evidence is available on the exploitation of date juice by acetic and gluconic fermentation for producing beverages. This review provides an overview of date fruit’s composition, the related health benefits for human health, vinegar and date-based fermented non-alcoholic beverages obtained by acetic acid bacteria fermentation.

A kinetic analysis of the aflatoxin detoxification potential of lactic acid bacteria in Terxine (a cereal-based food)

Aflatoxin B1 (AFB1) is a hazardous component that can seriously threaten the public health. Terxine is a component used in traditional soup and found in the western mountainous regions of Iran. Several microorganisms have been reported to bind or degrade aflatoxins (AFs) in foods and feeds. This research aimed to investigate the effect of Terxine fermentation by Lactobacillus plantarum strains AF1 and LU5 on AFB1. Fermentation was carried out, and pH, lactic acid and AFB1 amount and microbial count were further determined. In addition, the kinetic experimental data of AFB1 by L. plantarum AF1 and LU5 (obtained at 37°C) were fitted to the zero-order, first-order and parabolic diffusion models. According to the coefficient of determination (R2) and root mean square of errors (RMSE), the zero-order model best described AF degradation. The growth of Lactobacillus strains was increased by the rise in the fermentation time; in this regard, the number of L. plantarum AF1 increased from 4.2 to 5.1 log cfu/g and that of L. plantarum LU5 increased from 4.1 to 5.2 log cfu/g in the first 8 h, reaching 7.2 and 7.4 log cfu/g in the next 8 h, respectively. The results also showed that the amount of lactic acid increased whereas the pH value decreased during the 24 h fermentation. Both microorganisms reduced the amount of AFB1 while L. plantarum AF1 was more effective. Therefore, L. plantarum strains AF1 and LU5 can be effectively used to reduce AFB1 in fermented foods.

Analysis of the Sugar Content in Food Products by Using Gas Chromatography Mass Spectrometry and Enzymatic Methods

The aim of this study is to develop and optimise a method of sugar content determination in food products. Date juice (syrup) was used as a sample natural food resource for the analysis because of its potential usage as an alternative substrate for a variety of fermentation processes. Hence, qualifying and quantifying its sugar content is a crucial step. Therefore, gas chromatography mass spectrometry (GCMS) was used as a pre-qualitative method to identify the types of sugar in the date sample. The results demonstrate that the analysed date juice contains glucose, fructose and sucrose. This analysis was obtained by measuring the retention time of individual standard sugar samples such as glucose, fructose, mannose and sucrose. In addition, the mass spectra of the standard and date juice samples contained characteristic fragments of glucose, fructose and sucrose. Thus, GCMS results determined the appropriate enzymatic assays for quantifying the sugars in date juice. These results were similar to those of the two enzymatic methods (standard enzymatic assay and measuring the change in pH by CL10 analyser). Therefore, they confirmed the identified sugars and provided the sugar contents of the sample. Consequently, sugar quantification results indicate that 1 g of date juice sample contains a total of 0.5275⁻0.5507 g of six-carbon sugars (glucose + fructose) and 0.064⁻0.068 g of sucrose. As a consequence, the total sugar content in 1 g of date juice is 0.600⁻0.615 g. These results are comparable to the sample analysis that is provided by the date juice production company.