Comparison of physicochemical and emulsifying properties of commercial pea protein powders.

BACKGROUND: There is an increasing trend in the food industry to utilize plant-based proteins. Pea protein (PP) is one such protein that is a promising alternative emulsifier. However, there is a significant functionality gap between laboratory and commercially produced PP that limits its usage. The physicochemical and emulsification properties of five commercial PP powders were characterized to better understand the functionality gap. RESULTS: Four of the five commercial powders displayed low solubility, high surface hydrophobicity, and an abundance of large insoluble aggregates. High-pressure homogenization was able to break up the aggregates, reduce surface hydrophobicity, and increase solubility. There was a significant correlation between the homogenized solubility and the emulsification properties of the commercial PPs. There was not a significant correlation between the emulsification properties and the other physicochemical properties (unhomogenized solubility, zeta potential, surface hydrophobicity, and interfacial tension). CONCLUSIONS: The conformational changes caused by the commercial isolation process may disrupt the correlations between the physicochemical and emulsification properties of PP. Solubility is a key physicochemical property to enable good emulsification properties for PP. Homogenization is an effective step to improve the solubility of commercial PP and therefore promote its functional properties before industrial usage. © 2021 Society of Chemical Industry.

Microbial successions are associated with changes in chemical profiles of a model refrigerated fresh pork sausage during an 80-day shelf life study.

Fresh pork sausage is produced without a microbial kill step and therefore chilled or frozen to control microbial growth. In this report, the microbiota in a chilled fresh pork sausage model produced with or without an antimicrobial combination of sodium lactate and sodium diacetate was studied using a combination of traditional microbiological methods and deep pyrosequencing of 16S rRNA gene amplicons. In the untreated system, microbial populations rose from 10(2) to 10(6) CFU/g within 15 days of storage at 4°C, peaking at nearly 10(8) CFU/g by day 30. Pyrosequencing revealed a complex community at day 0, with taxa belonging to the Bacilli, Gammaproteobacteria, Betaproteobacteria, Actinobacteria, Bacteroidetes, and Clostridia. During storage at 4°C, the untreated system displayed a complex succession, with species of Weissella and Leuconostoc that dominate the product at day 0 being displaced by species of Pseudomonas (P. lini and P. psychrophila) within 15 days. By day 30, a second wave of taxa (Lactobacillus graminis, Carnobacterium divergens, Buttiauxella brennerae, Yersinia mollaretti, and a taxon of Serratia) dominated the population, and this succession coincided with significant chemical changes in the matrix. Treatment with lactate-diacetate altered the dynamics dramatically, yielding a monophasic growth curve of a single species of Lactobacillus (L. graminis), followed by a uniform selective die-off of the majority of species in the population. Of the six species of Lactobacillus that were routinely detected, L. graminis became the dominant member in all samples, and its origins were traced to the spice blend used in the formulation.

Effect of white mustard essential oil on inoculated Salmonella sp. in a sauce with particulates.

White mustard essential oil (WMEO), from white mustard seed (Sinapis alba L.), is obtained by solvent extraction of defatted and wetted ground mustard; endogenous myrosinase catalyzes the hydrolysis of the glucosinolate sinalbin to yield 4-hydroxybenzyl isothiocyanate (4-HBITC), the antimicrobial component of WMEO. Sauce with particulates was made by mixing sauce, which served as the carrier for WMEO, with frozen vegetable and chicken particulates inoculated with Salmonella sp. WMEO (at 250 to 750 ppm of 4-HBITC) was able to reduce inoculated Salmonella counts by 0.8 to 2.7 log (CFU/g) in a frozen sauce with particulates in a dose-dependent manner, starting from the point of formulating the sauce through the microwave cooking step. High-pressure liquid chromatography-based analytical data confirmed that 4-HBITC was present in all of the samples in the expected concentrations and was completely hydrolyzed after the recommended cooking time in microwave ovens. In another experiment simulating unintentional abuse conditions, where the WMEO containing sauce with particulates was kept at room temperature for 5 h, WMEO (at 250 to 750 ppm of 4-HBITC) was able to reduce inoculated Salmonella counts from the point of first contact and up to 5 h by 0.7 to 2.4 log (CFU/g). Despite the known hydrolytic instability of the active component 4-HBITC, particularly at close to neutral pH values, WMEO was effective in controlling deliberately inoculated Salmonella sp. in a frozen sauce with particulates.