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This research aimed to investigate the characteristics of casein phosphopeptides in Chinese human milk, and their potential relationship to infant growth. Using the liquid chromatography-Orbitrap-mass spectrometry technique, a total of 15 casein phosphopeptides were identified from 200 human milk samples. Also, our results indicate that casein phosphopeptides were phosphorylated with only one phosphate. The relative concentrations of casein phosphopeptides at 6 months postpartum were increased compared with milk at 2 months (FDR < 0.05). Significantly positive correlations were observed between casein phosphopeptides and infant growth, as shown by four casein phosphopeptides were positively correlated with the infants' weight-for-age Z -scores (r s range from 0.20 to 0.29), and three casein phosphopeptides were positively correlated with the infants' length-for-age Z-scores (r s range from 0.19 to 0.27). This study is the first to reveal the phosphorylated level and composition of casein phosphopeptides in Chinese human milk, and their potential relationship with infant growth. [Display omitted] • First discovery of the composition of casein phosphopeptides in Chinese human milk. • Casein phosphopeptides in human milk were found to be hypo-phosphorylated. • Casein phosphopeptides increased with the duration of lactation. • Casein phosphopeptides were positively correlated to infant weight and length. [ABSTRACT FROM AUTHOR]

[Display omitted] • Ninety-four odor-active compounds were identified from HM by DHS-GC × GC-O-MS. • Nonanal and octanal were the most important odor-active compounds in most HM. • Fat content was closely related to the amounts of odor-active compounds in HM. • Aldehydes have most abundant species and the highest correlation with fat content. • HM odor attributes were contributed by synergistic effect of odor-active compounds. Odor is an important indicator of human milk (HM) quality, with a proven function. Here, the effect of inter-individual nutrient differences on key odor-active compounds (OACs) and odor attributes of HM samples was investigated using flavor analysis techniques and correlation network analysis. A total of ninety-four OACs were identified from 30 HMs, of which 24 key OACs could represent the basic odor characteristics of HMs. Fat content was closely related to the amounts of OACs, with aldehydes being the most abundant species and having the highest correlation with fat content. Of them, nonanal and octanal were the most important OACs in HM, having both high flavor dilution factor (2 ∼ 64, 4 ∼ 128) and odor activity values (<1 ∼ 37, 2 ∼ 36) in most samples. Additionally, different pattern of synergism between key OACs contribute to each odor attribute of HM. These findings will provide insights for subsequent in-depth studies of HM flavor. [ABSTRACT FROM AUTHOR]

• Stunning stress resulted in textural softening and poor water retention of fillets. • Stunning stress led to myofibril fragmentation and detachment from sarcolemma. • Stunning stress facilitated cathepsin B and L releases in myofibrils. • Myofibril segmentation and increased cathepsin contributed to fillet softening. This study aimed to investigate the effect of stunning stress on textural properties and water-holding capacity (WHC) of silver carp (Hypophthalmichthys molitrix) fillets and its underlying mechanisms based on intrinsic proteases activity, myofibril microstructure, and myowater dynamic measurements. The results suggested that compared with the non-stressful percussion, ice/water and gill cut stunning resulted in accelerated muscle tenderization with intensive myofibril disintegration and sarcolemma-myofibril detachments. Myowater mobility and distribution were altered by stunning stress, in which gill cut facilitated the migration of immobilized water and free water, thus enhancing the centrifugation loss. In addition, stunning stress promoted the activation of endogenous proteases and the release of cathepsin B and L from lysosomes to myofibrils, which showed significant (P < 0.01) correlations with decreased shear force and elevated myofibril fragmentation index of fillets. Therefore, faster accumulation of cathepsins and myofibril disintegration together contributed to the weakening of texture and WHC in stunning-stressed fish fillets. [ABSTRACT FROM AUTHOR]

This study investigated the biochemical changes (proteins degradation, total volatile basic nitrogen, biogenic amines, volatile organic compounds, nucleotides catabolism and related enzymes) of bighead carp samples inoculated with four different bacteria ( Shewanella putrefaciens , Aeromonas sobria , Acinetobacter bohemicus , and Pseudomonas helmanticensis ) during storage at 4 ± 1 °C. A. sobria exhibited the strongest proteolytic activity. A. sobria , P. helmanticensis , and S. putrefaciens were responsible for putrescine production, whereas S. putrefaciens was the sole producer of cadaverine. Alcohols and S-compounds were mainly released by A. sobria and S. putrefaciens , respectively. The fastest degradation rates of hypoxanthine riboside and hypoxanthine were found in samples inoculated with P. helmanticensis and S. putrefaciens . Inosine nucleosidase was mainly resulted by A. sobria , P. helmanticensis and S. putrefaciens , whereas xanthine oxidase was derived from both fish muscle and secretions of P. helmanticensis and S. putrefaciens . [ABSTRACT FROM AUTHOR]