Fermentation of Rubus dolichocarpus juice using Lactobacillus gasseri and Lacticaseibacillus casei and protecting phenolic compounds by Stevia extract during cold storage.

This study aimed to investigate the biological activities of Lactobacillus gasseri SM 05 (L. gasseri) and Lacticaseibacillus casei subsp. casei PTCC 1608 (L. casei) in the black raspberry (Rubus dolichocarpus) juice (BRJ) environment, and also the anti-adhesion activity against Salmonella typhimurium (S. typhimurium) in fermented black raspberry juice (FBRJ). Results showed significant anti-adhesion activity in Caco-2 epithelial cells. In the anti-adhesion process, lactic acid bacteria (LAB) improve intestinal health by preventing the adhesion of pathogens. Adding LAB to BRJ produces metabolites with bacteriocin properties. Major findings of this research include improved intestinal health, improved antidiabetic properties, inhibition of degradation of amino acids, and increase in the nutritional value of foods that have been subjected to heat processing by preventing Maillard inhibition, and inhibition of oxidation of foodstuff by increased antioxidant activity of BRJ. Both species of Lactobacillus effectively controlled the growth of S. typhimurium during BRJ fermentation. Moreover, in all tests, as well as Maillard's and α-amylase inhibition, L. gasseri was more effective than L. casei. The phenolic and flavonoid compounds increased significantly after fermentation by both LAB (p < 0.05). Adding Stevia extract to FBRJ and performing the HHP process showed convenient protection of phenolic compounds compared to heat processing.

Optimizing the Production of Probiotic Yogurt as a New Functional Food for Diabetics with Favorable Sensory Properties Using the Response Surface Methodology.

This study aimed to optimize the processing of probiotic yogurt supplemented with cumin essential oil (CEO), vitamin C, D3 (Vit D), and reduction of fermentation time using response surface methodology as a new functional food for diabetics with desirable sensory properties. The central composite design (CCD) was used to analyze the effect of these independent variables on the growth of the Lactobacillus plantarum A7 (LA7), starter culture, and overall acceptability. Differences between treatments were analyzed. The data were evaluated by analysis of variance at the significance level of 0.05. The effective concentration of CEO and fermentation time had the significant effect on the Lactobacillus plantarum A7 (LA7) number. Variance analysis and three-dimensional graphs show that almost the only effective factor on the overall acceptability of probiotic yogurt containing essential oil and vitamin D3 was CEO. According to the obtained data from the analysis, the optimal amount of independent variables for probiotic yogurt formulation such as CEO, D3, and fermentation time was 0.02% (v/v), 400 IU, and 9 h, respectively. This functional product can be considered an efficient food to reduce or eliminate the complications of diabetes.

GC-MS determination of the content of polycyclic aromatic hydrocarbons in bread and potato Tahdig prepared with the common edible oil.

The polycyclic aromatic hydrocarbon (PAH) content of the Tahdig of the breads and potatoes prepared with edible oil was determined by GC-MS. The Tahdigs of bread and potato were baked under the same condition (volume of any oil 40 cc, temperature 180 °C, time 30 min). Polycyclic aromatic hydrocarbon determination was performed by an Agilent 6890 N Gas chromatography with mass selective detector, equipped with a capillary column. The highest contents of PAHs in Tahdig of bread and Tahdig of potato were observed in canola with 550 ± 3.9 ng/kg and sesame with 408.3 ± 41 ng/kg. The mean of PAH content was significantly higher in the Tahdig of bread compared to the Tahdig of potato (p < 0.05). Among the 16 PAHs examined by GC/MS, 10 PAHs were detected. The amount of high molecular weight (HMW) PAHs were significantly more than low molecular weight (LMW) PAHs (p < 0.05). Benzo [b]fluoranthene and benz[a]anthracene concentrations were significantly more than the other detected compounds (p < 0.05). Due to high PAH contamination of both Tahdig groups, the consumption of Tahdig (any type) was not recommended.