Post-thawing metabolite profile and amino acid oxidation of thawed pork tenderloin by HVEF-A short communication

Effects of different electrostatic field intensities assisted controlled freezing point storage on water holding capacity of fresh meat during the early postmortem period

In this study, the effect of different intensity electrostatic fields on the water holding capacity (WHC) of fresh meat during the early postmortem period in controlled freezing point storage (CFPS) were investigated. Significantly lower cooking loss were found in low voltage electrostatic field (LVEF) and high voltage electrostatic field (HVEF) compared to the control group (CK) (p < 0.05). The myofibril fragmentation index and microstructure results suggested that the sample under HVEF treatment remained relatively intact. It has been revealed that the changes in actomyosin properties under electrostatic field treatment groups were due to the combination and dissociation of actomyosin binding into myofilament concentration, which consequently affects the muscle WHC. The study further demonstrated that the electrostatic field, especially HVEF, might increase the WHC of fresh meat by affecting the distribution of water molecules and physiochemical properties of actomyosin during the early postmortem period.

Effects of ultrasound-assisted thawing on lamb meat quality and oxidative stability during refrigerated storage using non-targeted metabolomics

The aim of this study was to evaluate the changes of ultrasound-assisted thawing on lamb meat quality and differential metabolite profiles during refrigerated storage. Compared with flow water thawing (FW), pH, a*, C*, and sulfhydryl content of lamb were significantly increased, while L*, drip loss and cooking loss were significantly decreased after ultrasound-assisted thawing (UT). On day 1 (UT1 and FW1) and day 7 (UT7 and FW7) in the UT and FW groups, principal component analysis explained 42.22% and 39.25% of the total variance. In this study, 44 (UT1 and FW1) and 47 (UT7 and FW7) differentially expressed metabolites were identified, including amino acids, carbohydrates and their conjugates, nucleic acids, carbonyl compounds and others. The results of this study provide data to clarify the differences between UT and FW, and lay a foundation for the application of ultrasound-assisted thawing in the meat industry.

Co-analysis of cucumber rhizosphere metabolites and microbial PLFAs under excessive fertilization in solar greenhouse

Fertilizer application is the most common measure in agricultural production, which can promote the productivity of crops such as cucumbers, but the problem of excessive fertilization occurs frequently in solar greenhouses. However, the effects of fertilization levels on cucumber rhizosphere soil microbes and metabolites and their relationships are still unclear. In order to determine how fertilization levels affect the rhizosphere microenvironment, we set up four treatments in the solar greenhouse: no-fertilization (N0P0K0), normal fertilization (N1P1K1), slight excessive fertilization (N2P2K2), and extreme excessive fertilization (N3P3K3). The results showed that fertilization treatments significantly increased cucumber yield compared to no-fertilization, but, the yield of N3P3K3 was significantly lower than that of N1P1K1 and N2P2K2. Fertilization levels had significant effects on rhizosphere microorganisms, and pH, NH₄ ⁺-N and AP were the main environmental factors that affected the changes in microbial communities. The total PLFAs, the percentages of fungi and arbuscular mycorrhizal fungi (AMF) were significantly reduced and bacteria percentage was significantly increased in N3P3K3 compared to other fertilization treatments. Differential metabolites under different fertilization levels were mainly organic acids, esters and sugars. Soil phenols with autotoxic effect under fertilization treatments were higher than that of N0P0K0. In addition, compared with soil organic acids and alkanes of N0P0K0, N2P2K2 was significantly increased, and N3P3K3 was not significantly different. This suggested that cucumber could maintain microbial communities by secreting beneficial metabolites under slight excessive fertilization (N2P2K2). But under extremely excessive fertilization (N3P3K3), the self-regulating ability of cucumber plants and rhizosphere soil was insufficient to cope with high salt stress. Furthermore, co-occurrence network showed that 16:1ω5c (AMF) was positively correlated with 2-palmitoylglycerol, hentriacontane, 11-octadecenoic acid, decane,4-methyl- and d-trehalose, and negatively correlated with 9-octadecenoic acid at different fertilization levels. This indicated that the beneficial microorganisms in the cucumber rhizosphere soil promoted with beneficial metabolites and antagonized with harmful metabolites. But with the deepening of overfertilization, the content of beneficial microorganisms and metabolites decreased. The study provided new insights into the interaction of plant rhizosphere soil metabolites and soil microbiomes under the different fertilization levels.

Proteomics and Metabolomics Profiling of Pork Exudate Reveals Meat Spoilage during Storage

Previous studies have evaluated pork quality by omics methods. However, proteomics coupled with metabolomics to investigate pork freshness by using pork exudates has not been reported. This study determined the changes in the profiles of peptides and metabolites in exudates from pork stored at different temperatures (25, 10, 4, and −2 °C). Multivariate statistical analysis revealed similar changes in profiles in exudates collected from pork stored at −2 and 4 °C, and additional changes following storage at higher temperatures. We identified peptides from 7 proteins and 30 metabolites differing in abundance between fresh and spoiled pork. Significant correlations between pork quality and most of the peptides from these 7 proteins and 30 metabolites were found. The present study provides insight into changes in the peptide and metabolite profiles of exudates from pork during storage at different temperatures, and our analysis suggests that such changes can be used as markers of pork spoilage.

Use of mineral element profiling coupled with chemometric analysis to distinguish Zanthoxylum bungeanum cultivars and health risks of potentially toxic elements in pericarps

BACKGROUND

Zanthoxylum bungeanum pericarps (ZBP) are commonly used as food additives and traditional herbal medicines. Several mineral elements are known to have important physiological functions in organisms, whereas others are reported to have toxic effects. We determined levels of macro elements (Mg, S and Ca), essential trace elements (B, Mn, Fe, Cu, Zn, Se and Mo) and toxic elements (Ni, Al, Cr, As, Cd, Hg and Pb) in the pericarps of 19 Z. bungeanum cultivars. Hazard index values and incremental lifetime cancer risks were calculated to express health risks associated with pericarp consumption. Moreover, several chemometric analyses based on the mineral elements were used to distinguish Z. bungeanum cultivars.

RESULTS

The concentrations of 17 determined elements in the pericarps were ranked: Ca > Mg > S > Fe > Al > Mn > Zn > B > Cu > Ni > Pb > Cr > Mo > As > Cd > Hg > Se. The elements Zn, Cr and As had the highest variations in their concentrations. Cu, Mn, Se, Zn, Al, As, Cd, Cr, Hg, Ni and Pb posed some non-cancer risks, while As and Cd posed cancer risks. Mn, Fe, Zn, and Al were chosen as critical element markers for assessing ZBP using chemometric analyses.

CONCLUSION

Chemometric analyses could highlight mineral concentration differentiation among the 19 cultivars. The Z. bungeanum cultivar Z12 (from Wudu, Gansu) is best for producing ZBP, and cultivar Z18 (Guanling, Guizhou) can be a reference to classify and evaluate ZBP quality. The results provide valuable information for evaluating the potential safety risks of ZBP and contribute to inter-cultivar discrimination. © 2021 Society of Chemical Industry.

Integrated Physiological, Transcriptomic, and Metabolomic Analyses Revealed Molecular Mechanism for Salt Resistance in Soybean Roots

Salinity stress is a threat to yield in many crops, including soybean (Glycine max L.). In this study, three soybean cultivars (JD19, LH3, and LD2) with different salt resistance were used to analyze salt tolerance mechanisms using physiology, transcriptomic, metabolomic, and bioinformatic methods. Physiological studies showed that salt-tolerant cultivars JD19 and LH3 had less root growth inhibition, higher antioxidant enzyme activities, lower ROS accumulation, and lower Na+ and Cl- contents than salt-susceptible cultivar LD2 under 100 mM NaCl treatment. Comparative transcriptome analysis showed that compared with LD2, salt stress increased the expression of antioxidant metabolism, stress response metabolism, glycine, serine and threonine metabolism, auxin response protein, transcription, and translation-related genes in JD19 and LH3. The comparison of metabolite profiles indicated that amino acid metabolism and the TCA cycle were important metabolic pathways of soybean in response to salt stress. In the further validation analysis of the above two pathways, it was found that compared with LD2, JD19, and LH3 had higher nitrogen absorption and assimilation rate, more amino acid accumulation, and faster TCA cycle activity under salt stress, which helped them better adapt to salt stress. Taken together, this study provides valuable information for better understanding the molecular mechanism underlying salt tolerance of soybean and also proposes new ideas and methods for cultivating stress-tolerant soybean.

Metabolomics reveals the mechanism of Antarctic yeast Rhodotorula mucliaginosa AN5 to cope with cadmium stress

Heavy metal pollution in Antarctica has far exceeded expectations. Antarctic yeast is widely present in polar marine environment. The mechanisms of metabolomics effect of heavy metal on polar yeast have not been reported previously. In this study, gas chromatography-mass spectrometry (GC-MS) wascarried out to performed the metabolite profiling analysis of Antarctic sea-ice yeast Rhodotorula mucilaginosa AN5 exposed to different cadmium (Cd) stresses of 5 mM (HM5), 10 mM (HM10) and 20 mM (HM20), respectively. Metabolic profile analysis showed that the composition and contents of cellular metabolites have been altered by cadmium. 93 different metabolites were identified altogether, among which 23, 58 and 81 different metabolites were found in HM5, HM10 and HM20 group respectively. MetaboAnalyst analysis showed that in HM5, HM10 and HM20 groups, 12, 24 and 31 metabolic pathways were involved in the stress of cadmium to R. mucilaginosa, respectively. By contrasting with Kyoto Encyclopedia of Genes and Genomes database, we discovered that exposure of yeast AN5 to Cd stress resulted in profound biochemical changes including amino acids, organic acids and saccharides. These results will supply a nonnegligible basis of studying the adaptive resistance mechanism of Antarctic yeast Rhodotorula mucilaginosa to heavy metal.

Volatile Oil Profile of Prickly Ash (Zanthoxylum) Pericarps from Different Locations in China

Volatile oils of prickly ash (Zanthoxylum) pericarps have various potential biological functions with considerable relevance to food, pharmacological, and industrial applications. The volatile profile of oils extracted from prickly ash pericarps obtained from 72 plantations in China was determined by gas chromatography and mass spectrometry. Several chemometric analyses were used to better understand the volatile oil profile differences among different pericarps and to determine the key factors that affected geographical variations in the main volatile constituents of oils. A total of 47 constituents were detected with D-limonene, alfa-myrcene, and linalool as the most abundant. The volatile profile of pericarp oils was significantly affected by prickly ash species and some environmental factors, and the key factors that affected volatile profile variations for different prickly ash species were diverse. Chemometric analyses based on the volatile oil profile could properly distinguish Z. armatum pericarps from other pericarps. This study provides comprehensive information on the volatile oil profile of pericarps from different prickly ash species and different plantations, and it can be beneficial to a system for evaluating of pericarp quality. Moreover, this study speculates on the key environmental factors that cause volatile oil variations for each species, and can help to obtain better prickly ash pericarp volatile oils by improving the cultivated environments.

Biomedical Applications of Electromagnetic Detection: A Brief Review

This paper presents a review on the biomedical applications of electromagnetic detection in recent years. First of all, the thermal, non-thermal, and cumulative thermal effects of electromagnetic field on organism and their biological mechanisms are introduced. According to the electromagnetic biological theory, the main parameters affecting electromagnetic biological effects are frequency and intensity. This review subsequently makes a brief review about the related biomedical application of electromagnetic detection and biosensors using frequency as a clue, such as health monitoring, food preservation, and disease treatment. In addition, electromagnetic detection in combination with machine learning (ML) technology has been used in clinical diagnosis because of its powerful feature extraction capabilities. Therefore, the relevant research involving the application of ML technology to electromagnetic medical images are summarized. Finally, the future development to electromagnetic detection for biomedical applications are presented.

The use of mutton in sausage production

The work analyzes the quality of sausage with mutton. The proportion of individual commodities was as follows 40% sheep thigh, 40% pork shoulder, and belly 20%. The protein content in pork shoulder was 20.11 g.100g-1 in sheep thigh 23.65 g.100g-1 and sausage 19.89 g.100g-1. Of the monitored amino acids, the highest content was in lysine, in the sausage was 1.9 g.100g-1 and of the raw materials in the belly 2.1 g.100g-1. We also found a higher proportion of leucine 1.7 g.100g-1 in both sausage and sheep thighs. The arginine content in the sausage was also high 1.39 g.100g-1. We found a high content of palmitic acid in the pork shoulder of 24.38 g.100g-1 FAME. The content of palmitic acid in sheep meat was 24.32 g.100g-1 FAME and in sausage 24.16 g.100g-1 FAME. The content of stearic acid in the pork shoulder was 10.89g.100g-1 FAME, in the sheep thigh 10.64g.100g-1 FAME, in the belly 11.07 g.100g-1 FAME, and the sausage 10.92 g.100g-1 FAME. The MDA content in sheep meat was 0.185 mg.kg-1, in pork shoulder 0.141 mg.kg-1, in pork belly 0.22 mg.kg-1 and in sausage on the day of production 0.45 mg.kg-1. On the 30th day, the MDA content was in the sausage 0.78 mg.kg-1. The high MDA content of the sausage was probably most influenced by the technological process, as all raw materials, because there was a lower MDA content.

Alkylamide Profiling of Pericarps Coupled with Chemometric Analysis to Distinguish Prickly Ash Pericarps

Because of extensive cultivation areas, various cultivars, nonstandard naming notations, and morphology similarity among relative cultivars, adulteration and associated business fraud may happen in the marketplaces of prickly ash pericarps due to higher financial gain and high-frequency trading. This study presents variations in the chemical components and contents of different prickly ash species from different plantations. Alkylamide profiling of pericarps derived from Zanthoxylum armatum, Z. bungeanum, and some relative Zanthoxylum species from 72 plantations across China were tested using ultra-performance liquid chromatography. Then, several chemometrics were applied to classify the prickly ash pericarps to reveal potential indicators that distinguish prickly ash pericarps and to identify the key factors that affect pericarp alkylamide profiling. The dominating alkylamides in the prickly ash pericarps were Z. piperitum (ZP)-amide C (0–20.64 mg/g) and ZP-amide D (0–30.43 mg/g). Alkylamide profiling of prickly ash pericarps varied significantly across species and geographical variations. ZP-amide D in prickly ash pericarps was identified as a potential indicator to distinguish prickly ash species. Longitude and aluminum content in soils were identified as key factors that affected alkylamide profiling of prickly ash pericarps. This study provides a useful tool to classify prickly ash species based on pericarp alkylamide profiling and to determine the key influence factors on pericarp alkylamide variations.

Effect of multi-frequency ultrasound thawing on the structure and rheological properties of myofibrillar proteins from small yellow croaker

The influence of multi-frequency combined ultrasound thawing on primary, secondary, and tertiary structures, electrophoresis pattern, particle size distribution, zeta potential values, thermal stability, rheological behavior, and microstructure of small yellow croaker myofibrillar proteins (MPs) were studied. Four treatments were used for thawing small yellow croakers: flow water thawing (FWT), mono-frequency ultrasonic thawing (MUT), dual-frequency ultrasonic thawing (DUT), and tri-frequency ultrasonic thawing (TUT). Compared with fresh samples (FS), the MPs of the sample pretreated by DUT had non-significant effect on protein primary (including free amino groups and surface hydrophobicity), secondary, tertiary structures, electrophoresis pattern, and microstructure. MPs pretreated by DUT had less aggregation and degradation. Besides, DUT treatment increased the thermal stability of MPs. The ultrasound had significant effects on the rheological properties of MPs. Overall, DUT effectively minimized the changes in MPs structure and protected the protein thermal stability and rheological behavior during the thawing process.

Fatty Acid Profiling and Chemometric Analyses for Zanthoxylum Pericarps from Different Geographic Origin and Genotype

Zanthoxylum plants, important aromatic plants, have attracted considerable attention in the food, pharmacological, and industrial fields because of their potential health benefits, and they are easily accessible because of the wild distribution in most parts of China. The chemical components vary with inter and intraspecific variations, ontogenic variations, and climate and soil conditions in compositions and contents. To classify the relationships between different Zanthoxylum species and to determine the key factors that influence geographical variations in the main components of the plant, the fatty acid composition and content of 72 pericarp samples from 12 cultivation regions were measured and evaluated. Four fatty acids, palmitic acid (21.33-125.03 mg/g), oleic acid (10.66-181.37 mg/g), linoleic acid (21.98-305.32 mg/g), and linolenic acid (0.06-218.84 mg/g), were the most common fatty acid components in the Zanthoxylum pericarps. Fatty acid profiling of Zanthoxylum pericarps was significantly affected by Zanthoxylum species and geographical variations. Stearic acid and oleic acid in pericarps were typical fatty acids that distinguished Zanthoxylum species based on the result of DA. Palmitic acid, palmitoleic acid, trans-13-oleic acid, and linoleic acid were important differential indicators in distinguishing given Zanthoxylum pericarps based on the result of OPLS-DA. In different Zanthoxylum species, the geographical influence on fatty acid variations was diverse. This study provides information on how to classify the Zanthoxylum species based on pericarp fatty acid compositions and determines the key fatty acids used to classify the Zanthoxylum species.

Metabolomics characterizes metabolic changes of Apocyni Veneti Folium in response to salt stress

Apocyni Veneti Folium (AVF) has been raised great interest in the antioxidant properties recently for the preservation of human health. However, little research was found on the integrate metabolites except our previous investigation on the variations of the bioactive constituents. To understand the salt-tolerant mechanisms of the halophyte, metabolomic platform based on ultra-fast liquid chromatography tandem triple time-of-flight mass/mass spectrometer was applied in this study. The results showed that metabolic profiles were separated and differentiated among groups based on multivariate statistical analysis; different metabolites belonged to various chemical classes. Besides, phenylpropanoid pathway and terpenoid biosynthesis were disturbed in all salt-stressed AVF and low salt-treated group appeared to be better than other samples in terms of relative contents (peak areas) of the wide variety of bioactive components and physiological variations of photosynthetic pigments, osmotic homeostasis, lipid peroxidation product and antioxidative enzymes. This study may provide additional insight into the salt-tolerant mechanisms and the quality assessment of AVF in a holistic level based on the plant metabolomics.