Methenamine Hippurate

Seminal plasma composition has important role in sperm functionality and its freezability. The objective of this study was to test the hypothesis that seminal plasma (SP) oxidative status and metabolome are associated with fresh semen characteristics and freezability of bull sperm. To accomplish this objective, oxidative status markers and metabolome of SP of ejaculates obtained from 20 Holstein bulls (3 for each bull) were analyzed using spectrophotometry and nuclear magnetic resonance (¹H NMR). The ejaculates were classified into higher motility fresh semen (HMF) and lower motility fresh semen (LMF), according to total motility (TM) and progressive motility (PM) values of fresh semen. Then the ejaculates was cryopreserved and assigned to higher motility thawed group (HMT) or lower motility thawed group (LMT) according to TM and PM at 0 h post-thawing. Multivariate analyses were performed to identify the association between the functional characteristics of fresh and thawed semen and the SP parameters, in terms of the oxidative status and the metabolomic composition. According to our results, the advanced oxidative protein products (AOPP) and thiol concentrations in SP are significantly related to some physiological characteristics of the thawed sperm, such as higher viability, TM, PM and LIN and lower mitochondrial and cytoplasmic superoxide production in viable thawed cells. In contrast, a higher amount of C in the SP was negatively related to TM and PM of thawed semen and was associated with higher mitochondrial and cytoplasmic superoxide production. In addition, partial least squares-discriminant analysis (PLS-DA) performed on the ¹H NMR spectra indicated a discrete separation between HMF and LMF groups, and good discrimination between HMT and LMT groups. Higher levels of formic acid, lactate, glycerol and phosphocholine, were found in the SP of the HMF group than in the LMF group. On the other hand, alanine, phenylalanine, and tyrosine were higher in the SP of the LMF group than in the HMF group. GABA, glutamate, histidine and glycerol were found in higher concentrations in the HMT group than in the LMT group, while fructose decreased in the HMT group. Our results showed that the oxidative and metabolomic status of SP is related to the physiological properties of semen and its freezability and open new fields in research of SP biomarkers of bull semen preservation and fertility.

The objective of this experiment was to investigate the role of endogenous proteins and lipids in the structural and physicochemical properties of starch in heat‐moisture treatment (HMT) rice flour and to reveal their effect on starch digestibility under heat.

The findings indicate that, in the absence of endogenous proteins and lipids acting as a physical barrier, especially proteins, the interaction between rice flour and endogenous proteins and lipids diminished. This reduction led to fewer starch–protein inclusion complexes and starch–lipid complexes, altering the granule aggregation structure of rice flour. It resulted in a decrease in particle size, an increase in agglomeration between starch granules, and more surface cracking on rice granules. Under HMT conditions with a moisture content of 30%, slight gelatinization of the starch granules occurred, contributing to an increased starch hydrolysis rate. In addition, the elevated thermal energy effect of HMT enhanced interactions between starch molecular chains. These resulted in a decrease in crystallinity, short‐range ordering, and the content of double‐helix structure within starch granules. These structural transformations led to higher pasting temperatures, improved hot and cold paste stability, and a decrease in peak viscosity, breakdown, setback, and enthalpy of pasting of the starch granules.

The combined analysis of microstructure, physicochemical properties, and in vitro digestion characteristics has enabled us to further enhance our understanding of the interaction mechanisms between endogenous proteins, lipids, and starches during HMT. © 2024 Society of Chemical Industry.