Pyrazine yield and functional properties of rice bran protein hydrolysate formed by the Maillard reaction at varying pH

Regulation of Tetramethylpyrazine Formation by the Phenolics-Fenton Coupled Redox Cycling System

A novel technique for generating tetramethylpyrazine (TTMP) was proposed, carried out on a phenolics-Fenton coupled redox cycling system in an acetoin-ammonium acetate (AA-ACT) pattern reaction. The TTMP generation employing the Fenton system is a first-order reaction that significantly increased the reaction rate, especially in the early stages, distinguishing it from the original zero-order kinetics reaction pattern. Further, the Fenton reaction effectively promotes the TTMP generation at lower temperature, and epigallocatechin gallate (EGCG) could reset the Fenton reaction, accomplishing the redox cycle. We have discovered a novel class of intermediate products, N-substituted amides, which act as a "reservoir" and transform into amino acid, then undergo aromatization to generate TTMP. The results provide a useful supplement for intelligent synthesis route design, and a new approach for understanding the transformation pathways of pyrazines.

Nonenzymatic glycation as a tunable technique to modify plant proteins: A comprehensive review on reaction process, mechanism, conjugate structure, and functionality

Plant proteins are expected to become a major protein source to replace currently used animal-derived proteins in the coming years. However, there are always challenges when using these proteins due to their low water solubility induced by the high molecular weight storage proteins. One approach to address this challenge is to modify proteins through Maillard glycation, which involves the reaction between proteins and carbohydrates. In this review, we discuss various chemical methods currently available for determining the indicators of the Maillard reaction in the early stage, including the graft degree of glycation and the available lysine or sugar, which are involved in the very beginning of the reaction. We also provide a detailed description of the most popular methods for determining graft sites and assessing different plant protein structures and functionalities upon non-enzymatic glycation. This review offers valuable insights for researchers and food scientists in order to develop plant-based protein ingredients with improved functionality.

Effects of Reducing Sugars on the Structural and Flavor Properties of the Maillard Reaction Products of Lycium barbarum Seed Meal

Lycium barbarum seed meal contains a variety of bioactive compounds, but the use of L. barbarum seed meal in the food industry is rare. This study aimed to evaluate the effect of reducing sugars on the structural and flavor properties of the Maillard reaction products (MRPs) of the Lycium barbarum seed meal hydrolysate (LSH). The results showed that the flavors and tastes of the MRPs were affected by reducing sugars. In comparison to oligosaccharides, monosaccharides were more suitable for the development of MRPs with good sensory qualities. The structural characteristics of L. barbarum seed meal precursor MRPs were also affected by reducing sugars. The MRPs produced with the participation of monosaccharides had higher ultraviolet absorption and browning than the MRPs produced with oligosaccharides. The molecular weights of the MRPs were found to be 128-500 Da and 500-1000 Da. Compared to the MRPs made from other sugars, xylose-meridian products (X-MRPs) had a stronger meaty flavor. The mellowness and continuity of the MRPs made from monosaccharides were superior to those made from oligosaccharides. The MRPs formed by L. barbarum seed meal exhibited the characteristics of umami and meat flavor. MRPs with better flavors may be used to develop new types of seasoning salts.

Rice bran protein-based delivery systems as green carriers for bioactive compounds

Natural protein-based delivery systems have received special interest over the last few years. Different carriers are already developed in the food industry to protect, encapsulate and deliver bioactive compounds. Rice bran protein (RBP) is currently used as a carrier in encapsulating bioactives due to its excellent functional properties, great natural value, low price, good biodegradability, and biocompatibility. Recently, RBP-based carriers including emulsions, microparticles, nanoparticles, nanoemulsions, liposomes, and core-shell structures have been studied extensively in the literature. This study reviews the important characteristics of RBP in developing bioactive delivery systems. The recent progress in various modification approaches for improving RBP properties as carriers along with different types of RBP-based bioactive delivery systems is discussed. In the final part, the bioavailability and release profiles of bioactives from RBP-based carriers and the recent developments are described.