Flavor formation of tilapia byproduct hydrolysates in Maillard reaction.

The Maillard reaction (MR) of tilapia byproduct protein hydrolysates was investigated for the use of byproduct protein as a food ingredient and to mask its fishy odor and bitter flavor. The flavor differences in tilapia byproduct hydrolysates before and after the MR were analyzed to explore the key flavor precursor peptides and amino acids involved in MR. The results suggested that eight key volatile substances, including 2,5-dimethylpyrazine, 2-pentylfuran, hexanal, octanal, nonanal, (E)-2-decenal, decanal, and 1-octen-3-ol contributed most to the MR products group (ROAV > 1). Ten volatile compounds, including 1-octen-3-ol, hexanal, 2-pentylfuran, 2,5-dimethylpyrazine, methyl decanoate, and 2-octylfuran, were the flavor markers that distinguished the different samples (VIP > 1). The four most consumed peptides were VAPEEHPTL, GPIGPRGPAG, KSADDIKKAF, and VWEGQNIVK. Umami peptides and bitter free amino acids (FAAs) were the key flavor precursor peptide and FAAs, respectively. Overall, the hydrolysates of tilapia byproducts with flavor improved by MR are a promising strategy for the production of flavorings.

Antizyme inhibitor family: biological and translational research implications.

Metabolism of polyamines is of critical importance to physiological processes. Ornithine decarboxylase (ODC) antizyme inhibitors (AZINs) are capable of interacting with antizymes (AZs), thereby releasing ODC from ODC-AZs complex, and promote polyamine biosynthesis. AZINs regulate reproduction, embryonic development, fibrogenesis and tumorigenesis through polyamine and other signaling pathways. Dysregulation of AZINs has involved in multiple human diseases, especially malignant tumors. Adenosine-to-inosine (A-to-I) RNA editing is the most common type of post-transcriptional nucleotide modification in humans. Additionally, the high frequencies of RNA-edited AZIN1 in human cancers correlates with increase of cancer cell proliferation, enhancement of cancer cell stemness, and promotion of tumor angiogenesis. In this review, we summarize the current knowledge on the various contribution of AZINs related with potential cancer promotion, cancer stemness, microenvironment and RNA modification, especially underlying molecular mechanisms, and furthermore explored its promising implication for cancer diagnosis and treatment.

Induction Motor Stator Winding Inter-Tern Short Circuit Fault Detection Based on Start-Up Current Envelope Energy.

Inter-turn short circuit (ITSC) is a common fault in induction motors. However, it is challenging to detect the early stage of ITSC fault. To address this issue, this paper proposes an ITSC fault detection method for three-phase induction motors based on start-up current envelope energy. This approach uses Akima interpolation to calculate the envelope of the measured start-up current of the induction motor. A Gaussian window weighting is applied to eliminate endpoint effects caused by the initial phase angle, and the enveloping energy is obtained using the energy formula as the fault feature. Finally, by combining this with the support vector machine (SVM) classification learner, fault detection of ITSC in induction motors is achieved. The experimental results show that the average accuracy of this method reaches 96.9%, which can quickly and accurately detect ITSC faults in asynchronous motors and determine the severity of the faults. Furthermore, the average accuracy of SVM in detecting early ITSC faults under no-load conditions is 98.8%, which is higher than other classification learners, including LR, KNN, and NN. This study provides a new idea for induction motor fault detection and can contribute to induction motor maintenance.

Improving the flavor of tilapia fish head soup by adding lipid oxidation products and cysteine.

Deodorization and umami enhancement are important challenges in promoting and consuming fish products. The aim of this study was to establish whether exogenous addition of oxidized lipids and cysteine can improve the fishy, umami and create a characteristic flavor in tilapia fish head soup. The results revealed that adding oxidized lipids and cysteine enhanced the sensory attributes of fish head soup and promoted the production of pleasant-tasting amino acids and fewer bitter amino acids in the Maillard reaction. Additionally, the combination increased the levels of well-flavored aldehydes, esters, heterocyclic compounds and less hydrocarbons in the fish head soup. Among the 13 volatile compounds screened, nine were identified as characteristic aromas of fish head soup, including nonanal, (E,E)-2,4-decadienal, 1-octen-3-ol, (E)-2-decenal, acetic acid, hexanal, heptanal, 2-octenal, and decanal. Exogenous lipid oxidation products, fatty acid oxidation, and Maillard reaction can improve the aroma and umami of tilapia fish head soup.

Identification and virtual screening of novel salty peptides from hydrolysate of tilapia by-product by batch molecular docking.

Introduction: Tilapia produces a large number of by-products during processing, which contain potentially flavorful peptides. Methods: The application of PyRx software enabled batch molecular docking andscreening of 16 potential salty peptides from 189 peptides identified in the enzymaticdigestion of tilapia by-products. Results: According to sensory analysis, all 16 peptides werepredominantly salty with a threshold of 0.256 - 0.379 mmol/L with some sournessand astringency, among which HLDDALR had the highest salty intensity, followedby VIEPLDIGDDKVR, FPGIPDHL, and DFKSPDDPSRH. I addition, moleculardocking results showed these four core peptides with high salt intensity bound to thesalt receptor TRPV1 mainly via van der Waals interactions, hydrogen bonds, andhydrophobic forces; Arg491, Tyr487, VAL441, and Asp708 were the key sites for thebinding of salty peptides to TRPV1. Therefore, the application of batch moleculardocking using PyRx is effective and economical for the virtual screening of saltypeptides.

A novel mechanism for A-to-I RNA-edited AZIN1 in promoting tumor angiogenesis in colorectal cancer.

Adenosine (A) to inosine (I) RNA editing catalyzed by adenosine deaminases acting on RNA (ADAR) enzymes is a post-transcriptional modification that emerged as a key player in tumorigenesis and cancer progression. Antizyme inhibitor 1 (AZIN1) is one of the most frequent A-to-I RNA alterations in many human cancers. RNA-edited AZIN1 is known to confer a gain-of-function phenotype associated with aggressive tumors. However, the functional impact of RNA-edited AZIN1 in cancer angiogenesis remains unexplored. We showed here that RNA-edited AZIN1 promoted tumor angiogenesis through the upregulation of IL-8 via in vitro and in vivo experiments. And we subsequently demonstrated that delaying c-Myc degradation by OAZ2-mediated ubiquitin-independent proteasome pathway contributed to increase mRNA level and the secretion of angiogenic factor IL-8. Our study suggests an important contribution of RNA-edited AZIN1 to the tumor vascular microenvironment and highlights its translational potential. Thus, we revealed a potential approach to explore small-molecule antagonists such as reparixin attenuating IL-8 signaling for treatment of human cancer patients detected with hyper-editing.