Selection of Lactic Acid Bacteria with In Vitro Probiotic-Related Characteristics from the Cactus Pilosocereus gounellei (A. Weber ex. K. Schum.) Bly. ex Rowl

Pilosocereus gounellei (A. Weber ex. K. Schum.) Bly. ex Rowl., popularly known as xique-xique, is a cactus from the Caatinga biome, which is rich in bioactive compounds but has not been previously studied as a source of lactic acid bacteria (LAB) with probiotic aptitudes. This study aimed to identify, characterize, and select LAB isolates with in vitro probiotic-related characteristics from xique-xique cladodes and fruit. Isolates with the most promising probiotic-related characteristics were evaluated regarding their in vitro technological properties and capability of surviving in chestnut milk, whey protein drink, and mate tea with mint during 21 days of refrigeration storage. Seventeen recovered isolates had typical characteristics of LAB. Six out of these seventeen LAB isolates passed the safety tests and were included in experiments to evaluate the in vitro probiotic-related characteristics. Based on the results of a principal component analysis, the isolates 69, 82, 98, and 108 had the best performances in experiments to evaluate the probiotic-related characteristics. In addition to showing good technological properties, the four selected LAB isolates had high viable counts (>7.3 log cfu/mL) and high sizes of physiologically active cell subpopulations in chestnut milk, whey protein drink, and mate tea during refrigeration storage. These four isolates were identified by 16S-rRNA sequencing as being Lacticaseibacillus paracasei or Lacticaseibacillus casei. The results indicate xique-xique as a source of potentially probiotic LAB isolates.

Effect of viscosity on electrical conductivity in liquid foods

The electrical conductivities of foods affect their heating with ohmic heating and microwaves, and are required for electrical tomography studies. A range of model foods consisting of solutions of sodium carboxymethyl cellulose (NaCMC), NaCMC + sugars, concentrated skim milk, whey protein and viscous sugar solutions, with various amounts of electrolytes were prepared. The electrical conductivity was measured using a parallel plate sensor connected to an RCL meter using an a.c. voltage. The conductivity was found to increase with concentration, but was reduced by the effects of viscosity on ion mobility. The conductivity was closely related to bulk viscosity for sugar solutions following the modified Walden equation, but was unrelated to the viscosity of NaCMC solutions. Instead an “ion-diffusion” viscosity was defined and calculated from the electrical conductivity data, and this was found to relate well to the expected viscosity of the solution to which ions are exposed at a molecular scale.

Development of Mayonnaise Technology Enriched with Milk Whey Protein

Цель работы – разработать технологию нового продукта с повышенным содержанием белка. В статье представлена технология производства майонеза, обогащённого сывороточным белком альбумином. При разработке технологической схемы производства майонеза с альбумином была принята традиционная схема, в которую были добавлены дополнительные операции по подготовке альбумина: размораживание (дефростация), обезвоживание. В ходе исследований были проведены выработки контрольного и трёх опытных образцов с различным процентным содержанием альбумина (5, 10 и 15%). По результатам проведённых исследований нами рекомендуется вводить в рецептуру майонеза не более 10% альбумина. По органолептическим показателям, влажности и кислотности разработанный нами продукт отвечает требованиям ГОСТ 31761-2012 «Майонезы и соусы майонезные. Общие технические условия». Мы считаем, что введение в рецептуру альбумина позволит увеличить в майонезе долю легкоусвояемого белка, что, несомненно, повысит пищевую и биологическую ценность готового продукта. The goal of the work is to develop the technology of a new product with an increased protein content. The technology for the production of mayonnaise enriched with whey protein albumin is presented in the article. When developing the technological scheme for the production of mayonnaise with albumin, a traditional scheme was adopted, in which additional operations for the preparation of albumin were added: defrosting (defrostation), sublimating. During the researches the production of control and three experimental samples with different percentages of albumin (5, 10 and 15%) was carried out. According to the results of the research carried out, we recommend introducing no more than 10% albumin into the mayonnaise formula. According to organoleptic indicators, humidity and acidity, the product developed by us meets the requirements of GOST 31761-2012 "Mayonnaise and mayonnaise sauces. General Specifications". We believe that the addition of albumin to the formula will increase the proportion of easily digestible protein in mayonnaise, which will undoubtedly increase the nutritional and biological value of the finished product.

Preparation and Characterization of Soy Isoflavones Nanoparticles Using Polymerized Goat Milk Whey Protein as Wall Material

Soy isoflavones (SIF) are a group of polyphenolic compounds with health benefits. However, application of SIF in functional foods is limited due to its poor aqueous solubility. SIF nanoparticles with different concentrations were prepared using polymerized goat milk whey protein (PGWP) as wall material. The goat milk whey protein was prepared from raw milk by membrane processing technology. The encapsulation efficiencies of all the nanoparticles were found to be greater than 70%. The nanoparticles showed larger particle size and lower zeta potential compared with the PGWP. Fourier Transform Infrared Spectroscopy indicated that the secondary structure of goat milk whey protein was changed after interacting with SIF, with transformation of α-helix and β-sheet to disordered structures. Fluorescence data indicated that interactions between SIF and PGWP decreased the fluorescence intensity. All nanoparticles had spherical microstructure revealed by Transmission Electron Microscope. Data indicated that PGWP may be a good carrier material for the delivery of SIF to improve its applications in functional foods.