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[This corrects the article DOI: 10.3389/fnut.2022.926814.].

BackgroundDonor human milk should be processed to guarantee microbiological safety prior to infant feeding, but this process can influence the structure and quantity of functional proteins.ObjectiveThe aim of this study was to determine the effect of thawing, homogenization, vat-pasteurization (Vat-PT), retort sterilization (RTR) and ultra-high-temperature (UHT) processing on the structure of bioactive proteins in donor milk.MethodsPooled donor milk was either not treated (Raw) or treated with an additional freeze-thaw cycle with and without homogenization, Vat-PT, RTR with and without homogenization, and UHT processing with and without homogenization. Overall protein retention was assessed via sodium-dodecyl sulfate (SDS-PAGE), and the immunoreactivity of 13 bioactive proteins were assessed via enzyme-linked immunosorbent assay (ELISA).ResultsFreeze-thawing, freeze-thawing plus homogenization and Vat-PT preserved all the immunoglobulins (sIgA/IgA, IgG, IgM) in donor milk, whereas RTR and UHT degraded almost all immunoglobulins. UHT did not alter osteopontin immunoreactivity, but Vat-PT and retort decreased it by ~50 and 70%, respectively. Freeze-thawing with homogenization, Vat-PT and UHT reduced lactoferrin's immunoreactivity by 35, 65, and 84%, respectively. Lysozyme survived unaltered throughout all processing conditions. In contrast, elastase immunoreactivity was decreased by all methods except freeze-thawing. Freeze-thawing, freeze-thawing plus homogenization and Vat-PT did not alter polymeric immunoglobulin receptor (PIGR) immunoreactivity, but RTR, RTR plus homogenization and UHT increased detection. All heat processing methods increased α-lactalbumin immunoreactivity. Vat-PT preserved all the growth factors (vascular/endothelial growth factor, and transforming growth factors β1 and β2), and UHT treatments preserved the majority of these factors.ConclusionDifferent bioactive proteins have different sensitivity to the treatments tested. Overall, Vat-PT preserved more of the bioactive proteins compared with UHT or RTR. Therefore, human milk processors should consider the impact of processing methods on key bioactive proteins in human milk.

Partial digestion of milk proteins leads to the formation of numerous bioactive peptides. Previously, our research team thoroughly examined the decades of existing literature on milk bioactive peptides across species to construct the milk bioactive peptide database (MBPDB). Herein, we provide a comprehensive update to the data within the MBPDB and a review of the current state of research for each functional category from in vitro to animal and clinical studies, including angiotensin-converting enzyme (ACE)-inhibitory, antimicrobial, antioxidant, dipeptidyl peptidase (DPP)-IV inhibitory, opioid, anti-inflammatory, immunomodulatory, calcium absorption and bone health and anticancer activity. This information will help drive future research on the bioactivities of milk peptides. [ABSTRACT FROM AUTHOR]

Background: As many students face the enduring challenge of maintaining their motivation to complete homework assignments, there is a critical need to pay close attention to homework motivation management (i.e., students' efforts to sustain or enhance their motivation in order to complete homework assignments that might be boring or difficult). Yet, in spite of research showing that homework motivation has a powerful influence on homework performance and academic achievement, there have been few attempts to systematically investigate models of factors that influence homework motivation management. Purpose: The current investigation examines empirical models of motivation management for Chinese students in the context of math homework, with models informed by key motivation theories, including self-regulation of motivation, expectancy-value, and volitional control. Research Design: The study reported here used cross sectional survey data. Participants: The participants were 1,799 high school students from 46 classes in China. Results: Results from multilevel analyses indicated that, at the class level, motivation management was positively associated with homework interest, but was negatively associated with teacher feedback. At the student level, motivation management was positively related to managing emotion, managing time, students' interest in homework, cognitive reappraisal, expectancy belief, and time on sports. Meanwhile, motivation management was negatively associated with value belief and time on TV. Conclusion: The current investigation found that some results were in line with key motivation theories and related findings with U.S. students (e.g., managing time, and homework interest at the student level). In addition, it suggests that other results may be influenced by cultural and societal differences (e.g., gender, value belief, and teacher feedback). Consequently, it would be informative to pursue this line of research in cross-cultural settings. With respect to promoting student motivation in the homework process, it would be beneficial to pay more close attention to the role of homework interest, expectancy belief, and student initiatives (e.g., managing time, managing emotion, and cognitive reappraisal).