The browning phenomenon of fruits can be easily observed when fruits or vegetables (apples, pears, bananas, potatoes, etc.) are cut with a knife and the part turns brown. When this browning occurs, changes in taste, color, and nutrients usually are introduced. The cause of this browning phenomenon has been well studied for a long time, but these studies have mainly focused on preventing deterioration of processed foods during food processing or storage. Resultantly, there are few studies on how much changes in nutrients (saccharides, amino acids, fats, water-soluble low molecular weight ammonium ions, etc.) are caused by browning. The purpose of this study is to determine the change in nutrients during browning using apple as a model fruit. We conducted a comparative study on how much the nutrient fluctuations differ depending on the presence or absence of pretreatment such as the application of heat. All analysis was conducted using ¹H NMR. The ANOVA analysis showed that the concentrations of 4 amino acids (alanine, asparagine, isoleucine, and valine), 3 types of sugars (fructose, glucose, and xylose), 1 type of organic acid (lactate) and choline were significantly increased in samples showing browning. In addition, the groups before and after browning were clearly separated using multivariate statistical analysis methods (PCA, PLS-DA), which was greatly contributed by two sugar components (fructose and glucose) present in high concentrations in apples.

The SH3 domain found within a variety of proteins is comprised of generally 60 residues, and participated in protein-protein interactions with proline-rich motifs. Cobll1 was identified as a distinct molecular marker associated with CML progression, and PACSIN2 was discovered a novel Cobll1 binding partner through direct interaction between a SH3 domain of PACSIN2 and three proline-rich motifs of Cobll1. To understand the structural basis of interactions between PACSIN2 and Cobll1, backbone assignments of PACSIN2 SH3 domain were performed. Furthermore, three proline-rich peptides of Cobll1 were titrated to ¹⁵N-labeled PACSIN2 SH3 domain in various ratios. Our chemical shift changes data and conserved SH3 sequence alignment will be helpful to analyze fundamental molecular basis related to the interaction between PACSIN2 and Cobll1.