Starch and Protein Hydrolysis in Cooked Quinoa (Chenopodium quinoa Willd.) during Static and Dynamic In Vitro Oral and Gastric Digestion

Quinoa is a pseudocereal that has a favorable nutrient profile and may be a beneficial addition to the diet. To evaluate potential health-promoting properties of foods, it is important to...

Glycation of N-ε-carboxymethyllysine

The Maillard reaction is traditionally subdivided into three stages that start consecutively and run in parallel. Here, we show that N-ε-carboxymethyllysine (CML), a compound formed in the late stage of the reaction, can undergo a second glycation event at its secondary amino group leading to a new class of Amadori rearrangement products. When N-α-hippuryl-CML was incubated in the presence of reducing sugars such as glucose, galactose, ribose, xylose, maltose, or lactose in solution for 1 h at 75 °C, the compound was degraded by 6–21%, and N-ε-carboxymethyl-N-ε-deoxyketosyl lysine derivatives were formed. Under the same conditions, lysine was 5–10 times more reactive than CML. N-α-hippuryl-N-ε-carboxymethyl-N-ε-(1-deoxyfructosyl)-l-lysine (hippuryl-CMFL) and N-ε-carboxymethyl-N-ε-(1-deoxyfructosyl)-l-lysine (CMFL) were synthesized, isolated and characterized by MS/MS and NMR experiments. Depending on the reaction conditions, up to 21% of CMFL can be converted to the furosine analogue N-ε-carboxymethyl-N-ε-furoylmethyl-l-lysine (CM-Fur) during standard acid protein hydrolysis with hydrochloric acid. Incubation of bovine serum albumin (BSA) with glucose for up to 9 weeks at 37 °C revealed the formation of CMFL in the protein as assessed by HPLC–MS/MS in the MRM mode. Under these conditions, ca. 13% of lysine residues had been converted to fructosyllysine, and 0.03% had been converted to CMFL. The detection of glycation products of glycated amino acids (heterogeneous multiple glycation) reveals a novel pathway in the Maillard reaction.

Protein Hydrolysis by Subcritical Water: A New Perspective on Obtaining Bioactive Peptides

The importance of bioactive peptides lies in their diverse applications in the pharmaceutical and food industries. In addition, they have been projected as allies in the control and prevention of certain diseases due to their associated antioxidant, antihypertensive, or hypoglycemic activities, just to mention a few. Obtaining these peptides has been performed traditionally by fermentation processes or enzymatic hydrolysis. In recent years, the use of supercritical fluid technology, specifically subcritical water (SW), has been positioned as an efficient and sustainable alternative to obtain peptides from various protein sources. This review presents and discusses updated research reports on the use of subcritical water to obtain bioactive peptides, its hydrolysis mechanism, and the experimental designs used for the study of effects from factors involved in the hydrolysis process. The aim was to promote obtaining peptides by green technology and to clarify perspectives that still need to be explored in the use of subcritical water in protein hydrolysis.

Effect of Rumen Fluid Dosage and Fermentation Time on Dissolved Protein Levels of Vegetable Waste Silage for Vannamei Shrimp Feed

Specifically, the goal of this research was to evaluate the dissolved protein content of vegetable waste generated during the incubation of rumen fluid for use in (Whiteleg) vannamei shrimp diet. The results of the analysis of the degree of protein hydrolysis of vegetable waste treated with the addition of rumen fluid enzymes and different fermentation times of rumen fluid revealed that the addition of rumen fluid enzymes and different fermentation times of rumen fluid had a statistically significant effect (p0.05) on the degree of protein hydrolysis of vegetable waste. But there was no significant difference in the length of fermentation time or the interaction between the dosage of rumen fluid and the length of time (p>0.05) between the two groups. Duncan's test of rumen fluid dosage revealed that the degree of hydrolysis at a 1 percent dose was considerably greater (p0.05) than at 2 percent and 3 percent doses, and that the degree of hydrolysis at a 3 percent dose was significantly lower than at 2 percent

Dynamic In Vitro Gastric Digestion of Sheep Milk: Influence of Homogenization and Heat Treatment

Milk is commonly exposed to processing including homogenization and thermal treatment before consumption, and this processing could have an impact on its digestion behavior in the stomach. In this study, we investigated the in vitro gastric digestion behavior of differently processed sheep milks. The samples were raw, pasteurized (75 °C/15 s), homogenized (200/20 bar at 65 °C)–pasteurized, and homogenized–heated (95 °C/5 min) milks. The digestion was performed using a dynamic in vitro gastric digestion system, the human gastric simulator with simulated gastric fluid without gastric lipase. The pH, structure, and composition of the milks in the stomach and the emptied digesta, and the rate of protein hydrolysis were examined. Curds formed from homogenized and heated milk had much looser and more fragmented structures than those formed from unhomogenized milk; this accelerated the curd breakdown, protein digestion and promoted the release of protein, fat, and calcium from the curds into the digesta. Coalescence and flocculation of fat globules were observed during gastric digestion, and most of the fat globules were incorporated into the emptied protein/peptide particles in the homogenized milks. The study provides a better understanding of the gastric emptying and digestion of processed sheep milk under in vitro gastric conditions.

Application of the accelerated storage method for functional dry milk mixtures

В работе приведены результаты исследований сухой молочной смеси функционального назначения, подвергнутой хранению в течение 6 мес при аггравированных температурных режимах (20±2) °С, (35±2) °С, (55±2) °С и при постоянной относительной влажности воздуха 85 %. В результате было отмечено, что применение температуры хранения 55±2 °С позволяет подтвердить заявленный срок годности продукта с учетом коэффициента резерва, так как именно при данной температуре хранения отмечено изменение показателей окислительной порчи, гидролиза белка и органолептических показателей, которые оценивались по дескрипторно-профильному методу согласно ГОСТ ISO 16779-2017. The paper presents the results of studies of a dry milk mixture for functional purposes, stored for 6 months at aggravated temperature conditions (20±2) °C, (35±2) °C, (55±2) °C and at a constant relative air humidity of 85 %. As a result, it was noted that the use of a storage temperature 55±2 °C allows confirming the declared shelf life of the product, taking into account the reserve coefficient, since it is at this storage temperature that a change in indicators of oxidative deterioration, protein hydrolysis and organoleptic indicators, which were assessed by descriptor profile method according to GOST ISO 16779-2017.