High Fischer ratio oligopeptides in food: sources, functions and application prospects

ABSTRACT: High Fischer ratio oligopeptides (HFROs) are a group of oligopeptides containing high levels of branched-chain amino acids (BCAA) and low levels of aromatic amino acids (AAA). HFROs have received a lot of attention as they are believed to have significant physiological activities, including antioxidant, liver damage repair, anti-fatigue, anti-tumor and energy supply to the body. HFROs are available from a wide range of sources and both plant and animal proteins can be used to prepare HFROs but the physiological tolerability and rejection of special populations needs to be considered. Enzymatic hydrolysis is the most common method for the preparation of HFROs, but optimization of the separation and purification process is still needed in the future. Diseases caused by disruptions in the balance of BCAA and AAA in the blood, such as hepatic encephalopathy, can be treated by supplementing HFROs with drugs or food. In addition, HFROs are able to reduce fatigue feedback and assist in the treatment of phenylketonuria at the molecular nutrient level. The aim of this review is to review recent research on HFROs and provide new perspectives on the high value use of crops and the development of novel functional and special medical purpose foods

Genome-wide identification of alcohol dehydrogenase (ADH) gene family under waterlogging stress in wheat (Triticum aestivum)

Background Alcohol dehydrogenase (ADH) plays an important role in plant survival under anaerobic conditions. Although some research about ADH in many plants have been carried out, the bioinformatics analysis of the ADH gene family from Triticum aestivum and their response to abiotic stress is unclear. Methods A total of 22 ADH genes were identified from the wheat genome, and these genes could be divided into two subfamilies (subfamily I and subfamily II). All TaADH genes belonged to the Medium-chain ADH subfamily. Sequence alignment analysis showed that all TaADH proteins contained a conservative GroES-like domain and Zinc-binding domain. A total of 64 duplicated gene pairs were found, and the Ka/Ks value of these gene pairs was less than 1, which indicated that these genes were relatively conservative and did not change greatly in the process of duplication. Results The organizational analysis showed that nine TaADH genes were highly expressed in all organs, and the rest of TaADH genes had tissue specificity. Cis-acting element analysis showed that almost all of the TaADH genes contained an anaerobic response element. The expression levels of ADH gene in waterlogging tolerant and waterlogging sensitive wheat seeds were analyzed by quantitative real-time PCR (qRT-PCR). This showed that some key ADH genes were significantly responsive to waterlogging stress at the seed germination stage, and the response of waterlogging tolerant and waterlogging sensitive wheat seeds to waterlogging stress was regulated by different ADH genes. The results may be helpful to further study the function of TaADH genes and to determine the candidate gene for wheat stress resistance breeding

A 14-3-3 Protein-Encoding Gene, <i>BdGF14g</i>, Confers Better Drought Tolerance by Regulating ABA Biosynthesis and Signaling

Abscisic acid (ABA), a phytohormone, enacts a cardinal function in coping with abiotic stress. 14-3-3 proteins can interact with ABA-responsive-element-binding transcription factors (ABFs), a chief constituent of ABA signaling, and play critical roles in the dehydration response involving ABA signaling. Meanwhile, whether and how 14-3-3 proteins regulate ABA signaling to respond to aridity stress is yet to be fully investigated. Herein, BdGF14g, a 14-3-3 gene induced by ABA, H2O2, and PEG treatments, was identified in Brachypodium distachyon (B. distachyon). Overexpression of BdGF14g improved drought stress tolerance in tobacco plants, with a higher survival rate, longer root length, enhanced cell membrane stability, and increased antioxidase activity compared with non-transgenic controls in coping with dehydration. Both drought and exogenous ABA treatments resulted in smaller stomatal apertures in BdGF14g-transgenic lines. Additionally, when an ABA biosynthesis inhibitor was added, the better growth statuses, less H2O2 accumulation, and higher activities of catalase and superoxide dismutase under mannitol stress disappeared. Moreover, BdGF14g interacted with NtABF2, upregulated the endogenous ABA content, and enhanced the transcription of ABA-related genes, including NtNCED1, a crucial ABA biosynthesis gene, under drought conditions. In conclusion, BdGF14g acts as a positive factor in the water deficiency response by affecting ABA biosynthesis and signaling in tobacco plants

Towards rapidly quantifying and visualizing starch content of sweet potato [Ipomoea batatas (L.) Lam] based on NIR spectral and image data fusion

This study aimed to achieve the rapid quantification and visualization of the starch content in sweet potato via near-infrared (NIR) spectral and image data fusion. The hyperspectral images of the sweet potato samples containing 900-1700 nm spectral information within every pixel were collected. The spectra were preprocessed, analyzed and the 18 informative wavelengths were finally extracted to relate to the measured starch content using the multiple linear regression (MLR) algorithm, producing a good quantitative prediction accuracy with a correlation coefficient of prediction (rP) of 0.970 and a root-mean-square error of prediction (RMSEP) of 0.874 g/100 g by an external validation using a set of dependent samples. The MLR model was further verified in terms of soundness and predictive validity via F-test and t-test, and then transferred to each pixel of the original two dimensional images with the help of a developed algorithm, generating color distribution maps to achieve the vivid visualization of the starch distribution. The study demonstrated that the fusion of the NIR spectral and image data provided a good strategy for the rapidly and nondestructively monitoring the starch content of sweet potato. This technique can be applied to industrial use in the future.The authors acknowledge that this work was financially supported by Henan Province Science and Technology Project (No. 222102110113), Cooperation Project of Henan Institute of Science and Technology (No. 2021410707000060), High Talents Project of Henan Institute of Science and Technology (No. 2015015)