Food Chemistry Molecular Sciences最新文献

Falsified food directly influences wildlife, fair trade, religion, and the health of society. Here, we report a multiplex polymerase chain reaction to evaluate the accurate determination of seven species of bird meat in meals on a single assay platform. To amplify segments of DNA from Columba livia, Corvus moneduloides, Gallus gallus, Coturnix japonica, Phasianus colchicus, Struthio camelus, and Meleagris gallopavo meats, respectively, a total of seven sets of species-specific primers targeting the mitochondrial and cytochrome b genes were developed. Gel photographs and electrochromatography from an Experion Bioanalyzer were used to identify all PCR products. Species specificity checks discovered no cross-species amplification. The applicability of its screening to find target species in processed food was shown in commercial and model meatballs. A validation study revealed that the test is reliable, quick, affordable, repeatable, specific, and accurate down to 50,000 mitochondrial copies. It might be used for raw meats and products involving processed and severely deteriorated food samples. The customers, the food business, and law enforcement would all benefit immensely from this suggested approach.

An integrated analysis of the transcriptome and metabolome was conducted to investigate the underlying mechanisms of apple fruit response to impact damage stress. During the post-damage storage, a total of 124 differentially expressed genes (DEGs) were identified, which were mainly annotated in 13 pathways, including phenylpropanoid biosynthesis. Besides, 175 differentially expressed metabolites (DEMs), including 142 up-regulated and 33 down-regulated metabolites, exhibited significant alteration after impact damage. The DEGs and DEMs were simultaneously annotated in 7 metabolic pathways, including flavonoid biosynthesis. Key genes in the volatile esters and flavonoid biosynthesis pathways were revealed, which may play a crucial role in the coping mechanisms of apple fruit under impact damage stress. Moreover, 13 ABC transporters were significantly upregulated, indicating that ABC transporters may contribute to the transportation of secondary metabolites associated with response to impact damage stress. The results may elucidate the comprehension of metabolic networks and molecular mechanisms in apple fruits that have undergone impact damage.

Green tea processed from albino tea varieties often has umami taste and fresh aroma. This study identified green teas made from two types of albino tea cultivar, one having the white shoots (called Naibai, NB) and the other having the yellow shoots (called Huangjinya, HJY). Taste compounds analyses showed that galloylated catechins were highly concentrated in HJY green teas, whereas non-galloylated catechins and amino acids were more abundant in NB green teas. CsTA (involved in the catabolism of galloylated catechins) showed high expression in HJY tea shoots, resulting in gallic acid as a precursor for β-glucogallin biosynthesis being abundant in HJY. CsPDX2.1 (responsible for theanine hydrolyzation) had a lower expression level in NB than HJY shoots. Fatty acid–derived volatiles (FADVs), glycosidically bound volatiles (GBVs) and carotenoid–derived volatiles (CDVs) were highly concentrated in HJY green teas, whereas amino acids–derived volatiles were highly concentrated in NB green teas.

The aim of this study was to investigate the differences in the effects of mitochondria-involved energy metabolism and caspases activation on postmortem tenderness in different muscle fiber types. Beef Longissimus thoracis (LT) and Psoas major (PM) muscles showed significant difference in mitochondrial function. Our data revealed that PM suffered from higher levels of reactive oxygen species (ROS) earlier than LT, causing faster mitochondrial swelling and rupture. Additionally, faster metabolism of ATP-related compounds and activation of caspase-9 appeared in PM, but the activity of caspase-3 in PM was lower than that in LT. Differences in myofibril fragmentation index (MFI) of LT and PM at different aging stages suggested that energy metabolism and caspases activities may play a role in tenderness at different aging stages. These results indicated that oxidative stress-mitochondria-mediated tenderization process could be muscle-specific.

The presence of β-glucan in barley grains is one of its important quality traits. Lower β-glucan content is required for the barley used in beer and feed production, while higher β-glucan content is beneficial for food barley. Although intensive research has been carried out on the genotypic and environmental differences in β-glucan content in barley grains, little information is available on the molecular mechanisms underlying their genotypic differences and genetic regulation of β-glucan synthesis and accumulation. In this study, RNA sequencing analysis was conducted to compare the transcriptome profiles of two barley genotypes (BCS192 and BCS297) that greatly differ in grain β-glucan content, in order to identify the key genes responsible for β-glucan synthesis and accumulation during grain development. The results showed that carbohydrate metabolic processes and starch and sucrose metabolism play significant roles in β-glucan synthesis. The identified differently expressed genes (DEGs), which are closely associated with grain β-glucan content, are mainly involved in hydrolase activity and glucan metabolic processes. In addition, β-glucan accumulation in barley grains is predominantly regulated by photosynthesis and carbon metabolism. The DEGs identified in this study and their functions may provide new insights into the molecular mechanisms of β-glucan synthesis and genotypic differences in barley grains.

Fruit are susceptible to quality loss and deterioration after harvest due to high metabolic and physiological activities. Over the last four decades various postharvest treatments have ensured maintenance of quality, control of diseases or decay by slowing down the postharvest ripening and senesce. The fruit quality change during postharvest however, has been mostly explored using physicochemical characteristics. Considering the complexity of fruit physiology and metabolism, the application of omics techniques could aid the in-depth analysis and understanding of fruit quality change during postharvest treatment. Therefore, this review presents recent information on the application of integrated omics (transcriptomics, proteomics, and metabolomics) in postharvest research, with an overview on fruit quality and safety. Trends in omics data analysis for fruit during postharvest handling was highlighted. The role of integrated omics in improving our understanding of fruit response during natural postharvest progression (towards decay) during storage, as well as in case of induced responses due to the application of biocontrols was discussed. The article concluded with the outlooks of future studies on the application of integrated omics as the catalyst for innovative postharvest solutions.

Citrus sinensis orange juice is an excellent dietary source of β-carotene, a well-known antioxidant. However, β-carotene concentrations are relatively low in most cultivars. We developed a new orange through metabolic engineering strategy (GS) with 33.72-fold increase in β-carotene content compared to its conventional counterpart (CV). Using Caenorhabditis elegans, we found that animals treated with GS showed a greater reduction in intracellular reactive oxygen species (ROS) which is associated with a greater resistance to oxidative stress and induction of the expression of antioxidant genes. Moreover, animals treated with GS orange showed a more effective protection against β-amyloid proteotoxicity and greater hypolipidemic effect under high glucose diet compared to animals treated with CV. These data demonstrate that the increased amount of β-carotene in orange actually provides a greater beneficial effect in C. elegans and a valuable proof of principle to support further studies in mammals and humans.

Bioaccessibility analysis and antioxidant activity along in vitro digestion and a consumer-oriented sensory analysis were conducted in three potential functional foods based on Ca(II)-alginate beads containing bioactive compounds extracted from beet stems. Ca(II)-alginate beads per se, and two selected products (cookies and turkish delights supplemented with the beads) were prepared. Regarding the beads, among the attributes rated by consumers, visual appreciation predominates, being color in the just-as-right (JAR) category and in the like preference. Instead, both flavor and sweet taste were attributes highly penalized and should be improved in beads to be accepted as food per se. A higher percentage of customers preferred cookies and turkish delights instead of only beads, considering global satisfaction. Regarding in vitro digestion, there was a significant content of phenolic compounds in the products with beads, showing a bioaccessibility greater than 80% (for cookies) and 26% (for turkish delights). Also, the antioxidant capacity measured by ABTS ranged between 50 and 109% for cookies and turkish delights, being lower when measured by FRAP (between 20 and 30%, respectively). Thus, including the beads with beet stem extract in both products leads to a significant increase in the content of phenolic compounds and in the antioxidant capacity compared to their counterparts, protecting the compound during oral and gastric phases. These results allow the generation of improved Ca(II)-alginate systems with promising functional properties for the development of ingredients and functional foods.

Sesquiterpenes are important defensive secondary metabolites and aroma components. However, limited information is available on the mechanism of sesquiterpene formation and composition in the non-heading Chinese cabbage (NHCC) leaf. Therefore, headspace solid-phase microextraction/gas chromatography–mass spectrometry (HS-SPME/GC–MS) combined with transcriptome analysis was used to study the mechanism of volatile organic compound formation. A total of 26 volatile organic compounds were identified in two NHCC cultivars ‘SZQ’ and ‘XQC’ and their F1 hybrids. Among these, sesquiterpene β-caryophyllene was identified only in ‘XQC’ and F1. Five genes encoding caryophyllene synthase were identified. The candidate β-caryophyllene synthase genes BcTPSa11 and BcTPSa21 had high expression levels only in ‘XQC’ and F1. In addition, several transcription factors of MYB-related, MYB, bHLH, and AP2/ERF families were identified by co-expression, suggesting that they regulate β-caryophyllene biosynthesis. Our results provide a molecular basis for sesquiterpene biosynthesis as well as insights into the regulatory network of β-caryophyllene in NHCC.

Galactosyltransferase (GalT) is an important enzyme in synthesizing exopolysaccharide (EPS), the major polymer of biofilms protecting cells from severe conditions. However, the contribution to, and regulatory mechanism of GalT, in stressor resistance are still unclear. Herein, we successfully overexpressed GalT in Lactobacillus acidophilus NCFM by genetic engineering. The GalT activity and freeze-drying survival rate of the recombinant strain were significantly enhanced. The EPS yield also increased by 17.8%, indicating a positive relationship between freeze-drying resistance and EPS. RNA-Seq revealed that GalT could regulate the flux of the membrane transport system, pivotal sugar-related metabolic pathways, and promote quorum sensing to facilitate EPS biosynthesis, which enhanced freeze-drying resistance. The findings concretely prove that the mechanism of GalT regulating EPS biosynthesis plays an important role in protecting lactic acid bacteria from freeze-drying stress.