Cooking may affect the nutritional value of pork fat, and, nowadays, people have been paying an increasing amount of attention to the method of cooking. In this study, the effects of dietary pork fat cooked using different methods on body metabolism and intestinal microbes were studied in rats. Fat was extracted from pork belly meat cooked using three methods: braising (braising cooking method, BCM), stewing (SCM) and deep fat frying (DCM). The three types of pork fat were added to animal feed, and the effects of each on body weight, glucose and lipid metabolism, liver inflammation and intestinal microbes in rats were compared with the effects of soybean oil-treated feed (SO) and a blank control (BC). Rats in all three groups fed with cooked pork fat exhibited significant increases in body weight compared with the controls across the experimental feeding period. Furthermore, all three types of pork fat led to significant changes in the serum concentrations of triglycerides (TG) and total cholesterol (TC) relative to the controls, with the greatest increases in TG and TC in the BCM and DCM groups, respectively. All three types of pork fat led to significant decreases in serum high-density lipoprotein cholesterol concentrations relative to the controls, with the lowest concentration in the SCM group. All three types of pork fat also led to significant increases in low-density lipoprotein cholesterol concentrations relative to the controls, with the smallest increase in the DCM group. Rats in the SCM group had the highest level of liver fat deposition, followed by those in the BCM, DCM, SO and BC groups. Compared with the controls, the three groups fed with different types of cooked pork fat had significantly lower hepatic expression of nuclear transcription factor kappa B (NF-κB). The expression levels of NF-κB in the DCM and SO groups were significantly lower than those in the other groups. The abundance of Proteobacteria species in the intestines of rats was significantly lower in the BC group than in the other groups fed with cooked pork fat, and the abundance of Bacteroidetes species was significantly lower in the BCM, SCM and DCM groups than in the BC and SO groups. From the changes in the abundance of Firmicutes and Bacteroides, pork fat in the three cooking methods has a certain potential to promote the production of body obesity.

Dietary fat is an important part of human diet and has a close relationship with human health. However, it is still unclear how gut microbiota in adolescent responds to dietary fats at a normal dose. In this study, fat-free group (BC) was used as blank control group, we explored blood index and gut microbiota structure in growing rat(aged 1 months) after feeding a normal dose of 16.9% stewed lard(SL), refined lard(RL), fish oil(FO) and soybean oil(SO) for 6 weeks, respectively. The results showed that compared with RL group, SL group showed reduced fasting blood sugar and blood lipid levels and improved nutrient absorption capacity of the intestine. The blood indexes of glucose (Glu), total cholesterol (TC) and total triglyceride (TG) in FO treatment group were relatively low. The abundance of Bacteroidetes in the BC group decreased, and the abundance of Firmicutes increased. The Firmicutes/Bacteroidetes ratio of the FO group was relatively low, and the Firmicutes/Bacteroidetes ratio of the SL group and the SO group was lower than that of the RL group. The abundance of Bacteroidaceae in the SL group was increased. Research results showed that fat-free diets will increase the risk of obesity to a certain extent; compared with refined lard, stewed lard, soybean oil and fish oil can reduce the risk of obesity to a certain extent. The present study could find that the addition and types of dietary fat will affect the abundance and diversity of rat intestinal flora, and provide some information for nutritional evaluation about these dietary lipids.

A prepared dish needs to be reheated before eating, and various reheating methods affect its flavor quality. This study evaluated the influence of stir-frying reheating, steaming reheating and microwave reheating on moisture content, lipid oxidation and flavor profiles of prepared beef with tangerine peel. Stir-frying reheating samples obtained a higher moisture content and the highest thiobarbituric acid reactive substance value. Fifty-seven volatile compounds were identified by gas chromatography–mass spectrometry, of which fifteen compounds were considered as odor-active compounds with an odor activity value > 1. Aldehydes were the most prominent contributors to the aroma of reheated samples. Results revealed that stir-frying reheating samples had the most varieties of odor-active compounds, and the odor activity values of most of them were relatively higher. The heatmap analysis based on the odor activity values indicated that the stir-frying reheating process could maintain the original flavor of samples. A total of fifty-two volatile organic compounds were identified by gas chromatography–ion mobility spectrometry, and the principal component analysis revealed that the three reheated samples could be well distinguished from each other. Moreover, the content of free amino acids and nucleotides in stir-frying reheating samples was higher than that in other reheated samples. In conclusion, different reheating treatments affected the flavor quality of beef samples, and stir-frying process was better to obtain the aroma and taste characteristics of samples. The results of this study could provide useful information about the appropriate reheating method of a dish of prepared beef with tangerine peel for consumers, caterers and industrial production.

Huangjiu, one of the three oldest fermented beverages in the world, plays a significant role in shaping the flavor profile of braised pork. This study systematically investigated its impact by analyzing changes in key flavor precursors—including amino acids, nucleotides, and fatty acids—and by employing electronic nose (E-nose), electronic tongue (E-tongue), and GC–MS to monitor the overall flavor evolution during thermal processing. The results demonstrated that alanine made a substantial contribution to the overall taste of the braised pork. Furthermore, IMP exhibited a taste activity value (TAV) greater than 1, indicating its direct contribution to the umami taste of the dish. Principal component analysis (PCA) of the E-nose and E-tongue data revealed distinct overall aroma and taste profiles between the control group and the experimental group. Significant differences were observed in the responses of specific electronic nose sensors (W2W, W2S, W1W, W1C, W5S) and taste sensors (bitterness, umami, saltiness). By integrating odor activity value (OAV) analysis with variable importance in projection (VIP) scores, ten volatile compounds were identified as key differential markers distinguishing the two groups. These included (E,E)-2,4-nonadienal, ethanol, nonanal, octanal, heptanal, 1-octen-3-ol, citronellal, hexanal, (E)-2-octenal, and phenylethyl alcohol. Therefore, the deodorizing and aroma-enhancing effect of Huangjiu is manifested in two ways: it prevents the excessive oxidation of lipids that leads to off-odors (such as 1-octen-3-ol and octanal), and it either dissolves and volatilizes off-odor components or directly contributes aromatic compounds with floral and fruity notes—such as phenylethyl alcohol and citronellal—to enrich the overall aroma profile of the braised pork. Further correlation analysis elucidated the underlying relationships. The influence of Huangjiu on the flavor of braised pork was strongly associated with changes in the levels of amino acids and fatty acids, particularly unsaturated fatty acids (UFAs). Specifically, the content of off-odor compounds showed a significant negative correlation with UFA content, whereas the levels of desirable flavor compounds were significantly positively correlated with the content of amino acids such as histidine and glycine.

Anthocyanins were extracted from the petals of Loropetalum chinense var. rubrum, Petunia hybrida, and Rhododendron pulchrum Sweet, denoted as LA, PA and RA, respectively. Physicochemical properties of LA, PA and RA were comparatively evaluated. Among them, RA exhibited the highest total anthocyanin content (49.41 mg/g) along with the entire phenolic amount (102.01 mg/g). The obtained anthocyanins-rich extracts were immobilized into carrageenan (CP) and polyvinyl alcohol (PVA) matrices to develop intelligent packaging labels for Pork Meatball freshness monitoring. Scanning electron microscopy (SEM), X-ray diffraction (XRD), and fourier transform infrared spectroscopy (FTIR) analyses demonstrated excellent compatibility between anthocyanins and CP/PVA matrices, resulting in dense structures. The results of physicochemical and functional properties revealed that The prepared blank films and anthocyanin films containing RA (CP-RA film) showed optimal performance, including superior visible light/oxygen barrier properties, hydrophobicity, tensile strength (45.49 MPa), elongation at break (26.47%), antioxidant capacity (42.75%), and pH-sensitivity. In addition, CP-RA film maintained their superior color stability over various temperatures situations and displayed high sensitivity to changes in total volatile basic nitrogen (TVB-N) values.