Formulation and characterization of yogurt prepared with enzymatically hydrolyzed potato powder and whole milk powder.

This study highlights the optimization of a suitable amount of enzymatically hydrolyzed potato powder (EHPP) with whole milk powder (WMP) to produce a quality yogurt. The yogurt was prepared with different levels of EHPP (0, 10, 15, 20, 25, 35 and 50% w/w) with WMP and evaluated after 24 h at 4 °C. The resulted product was analyzed on the basis of physicochemical, sensory, texture, antioxidant activity and microbiological analysis. The prepared yogurt showed a significant (p < 0.05) decrease in pH, protein and fat while acidity, moisture and ash contents were increased compared with control yogurt. In addition, textural parameters like hardness and adhesiveness were decreased while no significant (p < 0.05) change was found in springiness and cohesiveness. Moreover, color parameters such as L * and a * values decreased while b * values were increased. The current study suggested that the yogurt sample supplemented with 25% EHPP of WMP certainly improved the physicochemical, texture, microstructure, color, antioxidant and sensory properties of yogurt with EHPP. The prepared yogurt with EHPP provided an excellent flavor, satisfying sweetness, and homogeneous texture. The yogurt prepared from the EHPP presented potential industrial applications. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s13197-021-05112-6.

Formulation of active packaging system using Artemisia scoparia for enhancing shelf life of fresh fruits.

An improved active packaging system was developed for fresh fruits using silver nanoparticles (AgNPs) coupled with calcium alginate (Ca-ALG). For the synthesis of AgNPs aqueous, ethanol and methanol extracts of Artemisia scoparia (AS) were used. These AgNP's were characterized using UV-Vis, SEM, EDS, AFM, FTIR and gel electrophoresis. Ethanol extract of AS (ASE) produced AgNPs with smallest size in comparison to aqueous AS (ASA) and methanol extract of AS (ASM). AgNPs synthesized from ASE had a size range of 12.0-23.3 nm and were tested on Human Corneal Epithelial Cells to evaluate their cytotoxicity. At 0.05 ng/mL of AgNP's concentration, no toxic effects were observed on the evaluated cell line. Therefore, 0.05 ng/mL of AgNPs mixed with edible coating of Ca-ALG were applied on strawberries and loquats as active coating to increase their shelf life. Significant improvement was observed in the quality parameters of strawberries and loquats such as microbial analysis, acidity loss, soluble solid content loss, weight loss and quality decay. Ca-ALG coating incorporated with AgNPs enhanced the shelf life of strawberries and loquats in comparison to no treatment and simple Ca-ALG coatings. This study provides an insight to food industry to extend the shelf life of fresh fruits using AgNP's formulated coatings.

Characterization of biofilm formation by Escherichia coli: An in vitro study

Objective: The purpose of the present study was to characterize the effects of medium, optical density (OD), andincubation time on biofilm formation by Escherichia coli in brain heart infusion (BHI) and Luria-Bertani broth(LB). Methods: The main procedure involved fixing the bacterial film with 95% ethanol, staining with 0.1% crystalviolet, releasing the bound dye with 33% glacial acetic acid, and measuring the OD of the solution at 570 nm using amicroplate reader. Results: It was found that 3 and 5 days of incubation are critical for biofilm formation as indicatedby the OD values of 0.55–0.35 and 0.70–0.39 in BHI and LB, respectively, at OD 0.05. Similarly, pattern in resultswas noted for OD 0.1 in both media BHI and LB. Conclusion: It is confirmed that 3 days (72 h) are required forobtaining effective biofilm formation in both BHI and LB at 37°C at OD 0.05 and 0.1.