This study aimed to evaluate the effect of cold storage on yamu fish meat (Brycon amazonicus). The methodology consisted of analyzing two temperatures (0±1.6°C and -8±1°C), two storage periods (13 and 61 hours) and two different sources (farm and river), and determine changes in the protein profile, micro structural, physical and chemical properties (water retention capacity-WRC, pH, texture of yamu meat fillets). The micro-structural changes were observed with optical and scanning electron microscopy. The results of the image analysis of the meat microstructure showed a negative effect from cold storage on the muscle, affecting the connective tissue. Otherwise, the analysis of protein profile demonstrated protein degradation during the cold storage of the yamu meat, such as for heavy chain myosin, actin and a-actinin. In addition, the origin of the fish and the storage temperature had a significant effect on the texture changes (P<0.05); meanwhile, the storage time had a significant effect on the three technological characteris tics of the meat (WRC, pH and texture) (P0.05).

Phenolic compounds and capsaicinoids present in different tissues (placenta, pericarp, and seeds) of the chili pepper fruit Capsicum annuum L. (cv. xcatik) cultivated in the Yucatán peninsula (Mexico) were analyzed. For this purpose, fresh and dehydrated chili peppers tissues were used. The phenolic compounds and capsaicinoids were extracted using ultrasound-assisted extraction (UAE) and compared to the maceration method. Extracts from each fruit tissue were studied for their antioxidant properties, and a phenolic profile of the whole fruit was performed using ultra-high-performance liquid chromatography with a photodiode array detector coupled to mass spectrometry (UPLC-PAD-ESI-MS). The xcatik chili pepper (XCP) presented a high content of phenolic compounds (11.67±3.34 mg GAE/g DW). The capsaicin:dihydrocapsaicin ratio was 2:1. Additionally, 17 phenolic compounds were detected in the extract of the whole fruit. This study provides a first scan of the phenolic composition and capsaicinoids content of the different tissues of the XCP fruit, as well as the correlation of these bioactive compounds with the antioxidant capacity, highlighting the recovery of bioactive compounds with great antioxidant power. Resumen. El contenido de compuestos fenólicos y capsaicinoides presentes en diferentes tejidos (placenta, pericarpio y semilla) de los frutos de chile Capsicum annuum L. (cv. xcatik) cultivados en la península de Yucatán (Mexico) fue analizado. Para dicho propósito, los tejidos frescos y deshidratados fueron evaluados. Los compuestos fenólicos y los capsaicinoides fueron extraídos usando la Extracción Asistida por Ultrasonido (EAU) y comparados con el método de maceración. Los extractos de cada tejido del fruto fueron estudiados con relación a sus propiedades antioxidantes, y el perfil fenólico del fruto completo fue realizado usando cromatografía líquida de ultra alta resolución con un detector de arreglo de fotodiodos y acoplado a espectrometría de masas (UPLC-PAD-ESI-MS). El chile xcatik (XCP) demostró ser un fruto con alto contenido de compuestos fenólicos (11.67±3.34 mg GAE/g peso seco). La relación capsaicina:dihidrocapsaicina fue 2:1. Adicionalmente, la presencia de 17 compuestos fenólicos fue detectada en el extracto del fruto completo. Este estudio proporciona un primer barrido de la composición fenólica y el contenido de capsaicinoides de los diferentes tejidos del fruto XCP, así como la correlación de estos compuestos bioactivos con la actividad antioxidante, resaltando la recuperación de compuestos bioactivos con un alto poder antioxidante.