Food Chemistry Molecular Sciences最新文献

To better determine how gamma irradiation (GI) improves abiotic stress resistance, a transcriptome analysis of postharvest L. edodes in response to 1.0 kGy GI was conducted, and further the underlying mechanism of GI in delaying quality deterioration over 20 d of cold storage was explored. The results suggested that GI was involved in multiple metabolic processes in irradiated postharvest L. edodes. In comparison with the control group, the GI group contained 430 differentially expressed genes, including 151 upregulated genes and 279 downregulated genes, which unveiled characteristic expression profiles and pathways. The genes involved in the pentose phosphate pathway were mainly upregulated and the expression level of the gene encoding deoxy-D-gluconate 3-dehydrogenase was 9.151-fold higher. In contrast, the genes related to other energy metabolism pathways were downregulated. Concurrently, GI inhibited the expression of genes associated with delta 9-fatty acid desaturase, ribosomes, and HSP20; thus, GI helped postpone the degradation of lipid components, suppress transcriptional metabolism and regulate the stress response. Additionally, the metabolic behavior of DNA repair induced by GI intensified by noticeable upregulation. These regulatory effects could play a potential and nonnegligible role in delaying the deterioration of L. edodes quality. The results provide new information on the regulatory mechanism of postharvest L. edodes when subjected to 1.0 kGy GI during cold storage.

This study aimed to identify the regulatory mechanisms of white, blue, red lights on carotenoid and tocochromanol biosynthesis in mung bean sprouts. Results showed that three lights stimulated the increase of the predominated lutein (3.2–8.1 folds) and violaxanthin (2.1–6.1 folds) in sprouts as compared with dark control, as well as β-carotene (20–36 folds), with the best yield observed under white light. Light signals also promoted α- and γ-tocopherol accumulation (up to 1.8 folds) as compared with dark control. The CRTISO, LUT5 and DXS (1.24–6.34 folds) exhibited high expression levels under light quality conditions, resulting in an overaccumulation of carotenoids. The MPBQ-MT, TC and TMT were decisive genes in tocochromanol biosynthesis, and were expressed up to 4.19 folds as compared with control. Overall, the results could provide novel insights into light-mediated regulation and fortification of carotenoids and tocopherols, as well as guide future agricultural cultivation of mung bean sprouts.

In the present study, l-tryptophan was applied in combination with blue light to modulate carotenoid biosynthesis in maize sprouts. The profiles of carotenoids, chlorophylls, and relative genes in carotenoid biosynthesis and light signaling pathways were studied. l-tryptophan and blue light both promoted the accumulation of carotenoids, and their combination further increased carotenoid content by 120%. l-tryptophan exerted auxin-like effects and stimulated PSY expression in blue light exposure maize sprouts, resulting in increased α- and β- carotenes. l-tryptophan could also play a photoprotective role through the xanthophyll cycle under blue light. In addition, CRY in the light signaling pathway was critical for carotenoid biosynthesis. These findings provide new insights into the regulation of carotenoid biosynthesis and l-tryptophan could be used in conjunction with blue light to fortify carotenoids in maize sprouts.

Linalool and its derivatives contribute greatly to tea aroma. Here, 8-hydroxylinalool was found to be one of the major linalool-derived aroma compounds in Camellia sinensis var. assamica ‘Hainan dayezhong’, a tea plant grown in Hainan Province, China. Both (Z)-8-hydroxylinalool and (E)-8-hydroxylinalool were detected, and the E type was the main compound. Its content fluctuated in different months and was the highest in the buds compared with other tissues. CsCYP76B1 and CsCYP76T1, located in the endoplasmic reticulum, were identified to catalyze the formation of 8-hydroxylinalool from linalool in the tea plant. During withering of black tea manufacturing, the content of both (Z)-8-hydroxylinalool and (E)-8-hydroxylinalool significantly increased. Further study suggested that jasmonate induced gene expression of CsCYP76B1 and CsCYP76T1, and the accumulated precursor linalool may also contribute to 8-hydroxylinalool accumulation. Thus, this study not only reveals 8-hydroxylinalool biosynthesis in tea plants but also sheds light on aroma formation in black tea.

In the present study, three matured Japanese plum cultivars with different colored peel and flesh were selected to mine the key transcription factors regulating anthocyanin formation in tissues. Results showed that PsMYB10 was correlated with structural genes C4H, F3H, and ANS. PsMYB6 could positively regulate C4H (r = 0.732) and accumulated anthocyanins in Sanhua plum’s flesh. Sanhua plum has the highest phenolic and anthocyanin contents (10.24 ± 0.37 gallic acid equivalent mg g⁻¹ dry weight (DW) and 68.95 ± 1.03 μg g⁻¹ DW), resulting itself superior biological activity as 367.1 ± 42.9 Trolox equivalent mg g⁻¹ DW in oxygen radical absorbance capacity value and 72.79 ± 4.34 quercetin equivalent mg g⁻¹ DW in cellular antioxidant activity value. The present work provides new insights into the regulatory mechanism of tissue-specific anthocyanin biosynthesis, confirming the pivotal role of anthocyanins in the biological activity of plums, providing essential support for the development of horticultural products enriched with anthocyanins.

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.