Targeted-metabolomic and untargeted-proteomic approaches reveal the effects of muscle fibre type and postmortem ageing on taste-active compounds in beef.

The taste of beef is caused by taste-active compounds detected in the mouth during mastication. We hypothesised that the concentration of taste-active compounds in beef is influenced by muscle-fibre-type and postmortem ageing. To test this, and unravel the underlying mechanisms, we investigated the taste-active compounds, and proteomic profiles, in beef masseter [oxidative muscle, all type I fibres) and cutaneous trunci (glycolytic muscle, mostly type II fibres) before and after 14-days postmortem ageing. Our results showed that nucleotides were initially higher and degraded slower in cutaneous trunci (P < 0.05 for both), which could be explained by the profile of nucleotide metabolism enzymes. In contrast, free amino acids were initially higher and increased more in masseter compared to cutaneous trunci (P < 0.05 for all), which might be explained by the profile and activity of proteases in these two muscles. Our results indicate the taste of beef is affected by the muscle-fibre-type and postmortem ageing.

Muscle fibre type composition influences the formation of odour-active volatiles in beef.

Flavour is a key driver of consumer liking, and odour-active volatiles formed in cooking are important contributors to the flavour of cooked beef. We hypothesised that the formation of odour-active volatiles in beef are influenced by the contents of type I oxidative and type II glycolytic muscle fibres. To test our hypothesis, we combined ground masseter (type I) and cutaneous trunci (type II) into beef patties, cooked them, then their volatile profiles were analysed using gas chromatography-mass spectrometry. Antioxidant capacity, pH, total heme protein, free iron, and fatty acid composition of these patties were also measured to investigate their relationship to volatile formation. Our study showed that beef composed of more type I fibres had higher 3-methylbutanal and 3-hydroxy-2-butanone, but less lipid-derived volatiles, and this could be partially attributed to the higher antioxidant capacity, pH, and total heme protein content in type I fibres. The results of our study indicate that fibre-type composition plays an important role in volatile formation and hence flavour of beef.

Alginate-inulin-chitosan based microspheres alter metabolic fate of encapsulated quercetin, promote short chain fatty acid production, and modulate pig gut microbiota.

Quercetin loaded alginate microspheres, fabricated with the inclusion of inulin as a prebiotic source and chitosan as protective coating (ALINCH-Q), were subjected to in vitro colonic fermentation using pig fecal microbiota, with empty microspheres ALINCH-E, unencapsulated quercetin UQ and media only Blank as parallel studies. ALINCH-Q altered quercetin biotransformation towards higher production of 3-hydroxyphenylpropionic acid and 3-hydroxyphenylacetic acid, and further metabolism of 3,4-dihydroxyphenylacetic acid and 4-hydroxyphenylacetic acid compared to UQ. In addition, ALINCH-Q but not ALINCH-E or UQ significantly promoted SCFAs production compared to Blank. Furthermore, the ALINCH-Q microspheres altered the microbial compositions, increased the relative abundance of Lactobacillus, Turicibacter, Eubacterium, and Clostridium, while decreased that of the potentially pathogenic Enterococcus. The results suggest an interplay between the dietary fiber matrix and quercetin in producing these effects, and that ALINCH-Q could serve as a potential targeted delivery vehicle for quercetin to exert beneficial biological effects in the colon.

Rinse and chill®, frozen storage and retail packaging influence the quality of lamb loins.

This study evaluated effects of Rinse&Chill® vs. control, storage condition (fresh, frozen-thawed) and retail packaging (high oxygen modified atmosphere packaging, vacuum skin packaging) on quality of lamb loins. Thirty-two lambs were slaughtered, and carcasses were allocated to Rinse&Chill® or control (n = 16 for each). Loins were aged for seven-days (fresh), and then allocated to fresh or freezing-thawing (frozen-thawed). After storage completion loins were cut into steaks then packaged in high oxygen modified atmosphere packaging (HiOxMAP) or vacuum skin packaging (VSP) and into 8-days simulated retail display. Rinse&Chill® samples had lower heme protein content and lipid oxidation (p < 0.05 for both) compared to control samples. In frozen-thawed lamb samples, VSP resulted in lower lipid oxidation, higher red values (a*), and lower Warner-Bratzler shear force compared to those in HiOxMAP (p < 0.05 for all). This study showed that Rinse&Chill® reduced lipid oxidation in lamb loins, and VSP can be used to improve the quality of frozen-thawed lamb in retail.

Consumer Characterization of Wet- and Dry-Aged Mutton Flavor Profile Using Check-All-That-Apply.

The aim of this study was to assess if consumers could characterize wet- and dry-aged mutton flavor profiles using CATA (check-all-that-apply). A flavor lexicon was developed for mutton, and consumers assessed wet- and dry-aged mutton patties against this lexicon using CATA methodology. Results indicate that consumers most often associated caramel and roasted flavors with dry-aged patties, and "sheepy" and metallic flavors with wet-aged patties. Volatile analysis supported the consumer characterization as there were more Maillard reaction products, including pyrazines, which are associated with roasted and cooked flavors, found in the dry-aged patty volatile profile. More 1-octen-3-one, which is associated with metallic flavors, was found in the wet-aged patty volatile profile. These results provide validation that the lexicon utilized in this study (i) is suitable for the characterization of mutton flavor and (ii) will have applications for future investigations into the flavor components driving consumer liking for mutton.

Volatile Profile of Dry and Wet Aged Beef Loin and Its Relationship with Consumer Flavour Liking.

This study investigated the effect of ageing method and ageing time on the volatile profiles of grilled beef striploins (Longissimus thoracis et lumborum) and their relationship with consumer flavour liking. Volatiles were measured in grilled steaks subjected to 35 days of dry ageing, 35 days of wet ageing, 56 days of dry ageing or 56 days of wet ageing, using headspace-solid-phase microextraction followed by gas chromatography-mass spectrometry. Gas chromatography-olfactometry-mass spectrometry was also conducted on 35-day wet and dry aged samples to identify volatiles with high odour impact. The concentration of many odour impact volatiles, e.g., 3-hydroxy-2-butanone, 2-acetyl-2-thiazoline, and various alkyl-pyrazines, was significantly higher in dry aged beef compared to wet aged beef (p < 0.05). Several odour impact volatiles, e.g., 2-acetyl-1-pyrroline, and alkyl-pyrazines, decreased significantly with ageing time (p < 0.05), while volatile products of lipid oxidation and microbial metabolism increased with ageing time. Partial least-squares regression analysis showed that the higher consumer flavour liking for 35-day dry aged beef was associated with higher concentrations of desirable odour-active volatiles.

Formononetin induces the mitochondrial apoptosis pathway in prostate cancer cells via downregulation of the IGF-1/IGF-1R signaling pathway.

Abstract Context: Formononetin, an isoflavone, can inhibit the proliferation of cancer cells, including those of the prostate. However, its antitumor mechanism remains unclear. Aim: To investigate whether the insulin-like growth factor 1 (IGF-1)/insulin-like growth factor 1 receptor (IGF-1 R) signaling pathway mediates the formononetin antitumor effect on prostate cancer cells. Materials and methods: The viability of PC-3 cells was measured by MTT assay 48 h after formononetin treatment (25, 50 and 100 µM). Formononetin-induced cell apoptosis was measured by Hoechst 33258 staining and flow cytometry. Expression of Bax mRNA was detected by real-time PCR, and the expression levels of Bax and IGF-1 R proteins were detected by western blots. Results: At concentrations >12.5 µM, formononetin significantly inhibited the proliferation of human prostate cancer cells. Formononetin increased Bax mRNA and protein expression levels and decreased the expression levels of pIGF-1 R protein in a dose-dependent manner. Conclusion: High concentrations of formononetin-induced apoptosis in androgen-independent prostate cancer cells through inhibition of the IGF-1/IGF-1 R pathway.