e aim of this study was to develop a chitosan/cellulose nano bril (CNF) nanocomposite and evaluate its e ect on strawberry's postharvest quality after coating. From the results of color, thickness, and scanning electron microscopy (SEM) and permeability to water vapor analyses, the best lm formulation for coating strawberries was determined. ree coating formulations were prepared: 1% chitosan, 1% chitosan + 3% CNF, and 1% chitosan + 5% CNF. e strawberries were immersed in the lmogenic solutions and kept under cold storage (1 ± 1°C). e color of the lm was not a ected by increased concentration of cellulose nano brils; however, the thickness and water vapor permeability were a ected by the CNF addition. e coating with the highest CNF concentration performed better in reducing fruit mass and rmness loss. e color was positively in uenced by the addition of the coating, regardless of formulation, as well as soluble solid content, PG enzymatic activity, and the fruit appearance. e pH and titratable acidity showed no signi cant di erence among treatments. It was observed that the vitamin C, phenolic compounds, and anthocyanin content, as well as the PAL activity and the antioxidant activity (except for % protection), were a ected by chitosan coating, however not by the addition of CNFs.

No abstract

RESUMOO pequi é consumido tradicionalmente cozido, podendo sofrer influência desse processo. Objetivou-se, neste trabalho, avaliar o efeito de diferentes tempos de cozimento sobre a qualidade do pequi. Os frutos oriundos do Norte de Minas Gerais foram selecionados, lavados, sanificados, descascados e submetidos a diferentes tempos de cozimento (0, 5, 10, 15, 20, 25, 30, 35 e 40 minutos). As análises foram realizadas no mesocarpo interno e na água de cozimento. Com o aumento do tempo de cozimento, observou-se, no fruto, diminuição da cor, firmeza e sólidos solúveis e dos minerais potássio, sódio, zinco e ferro, sendo esses minerais detectados na água. O cobre aumentou no mesocarpo interno e reduziu na água. Fósforo, cálcio, magnésio, manganês e enxofre não foram influenciados pelo tempo de cozimento. Vitamina C, carotenóides totais e ß-caroteno diminuíram proporcionalmente ao tempo de cozimento e desses, apenas a vitamina C foi encontrada na água de cozimento. Conclui-se que, mesmo com 40 minutos de cozimento, o pequi continua sendo importante fonte de nutrientes. Termos para indexação:Frutas do cerrado, valor nutricional, minerais, vitaminas. ABSTRACTCaryocar brasiliense Camb. fruits is traditionally consumed cooked; and may suffer influences from this process. Thus, the objective of this work was to evaluate the effect of different times of cooking on the quality of this fruit. The fruits from North of Minas Gerais (Brazil) were selected, washed, sanitized, peeled and submitted to different times of cooking (0, 5, 10, 15, 20, 25, 30, 35 and 40 minutes). The analyses were carried out at the internal mesocarp and in the cooking water. With the increase of cooking time, decrease of color, firmness and the minerals potassium, sodium, zinc and iron decreased in the fruit and were detected in the water. The copper increased in internal mesocarp and reduced in the water. Potassium, sodium, zinc and iron decreased in the fruit with increased time of cooking and were detected in the water. Copper increased in the internal mesocarp and decreased in water. Phosphorus, calcium, magnesium, manganese and sulfur were not influenced by cooking time. Vitamin C, total carotenoids and betacarotene decreased to the time of cooking and of these, only vitamin C was found in the cooking water. It was concluded that even with 40 minutes of cooking these fruits continues as an important source of nutrients.

This study evaluated the stability of strawberry pulp subjected to three factors, pasteurisation (pasteurised and unpasteurised), freezing method (static air and forced air) and storage time (0, 2, 4 and 6 months). Pasteurisation favoured vitamin C retention during storage but enhanced the total loss of phenolics without affecting anthocyanin levels. Freezing by forced air was more effective in retaining phenolics during the first 4 months of storage, although the freezing method did not affect the anthocyanin levels. Processing and storage reduced the levels of individual phenolics. Freezing by forced air was more effective than static air in retaining antioxidant activity of the pulp. Polyphenol oxidase and peroxidase enzyme levels were relatively stable and independent of pasteurisation, freezing and storage time. Even after 6 months of frozen storage, strawberry pulp is a significant source of nutrients and bioactive compounds and retains high antioxidant capacity independent of pasteurisation and freezing method.

This study evaluated the physicochemical characteristics and volatile profile of strawberry pulp subjected to factors, pasteurization (unpasteurized and pasteurized), freezing method (static air and forced air), and their interactions, during 12 months. Strawberry fruit were washed, sanitized, and pulped. The pulp was packaged, pasteurized, and frozen (0, 2, 4, 6, and 12 months). We concluded that pasteurization alters the strawberry pulp color. The impact of pasteurization and freezing method on the strawberry pulp pH, titratable acidity, and soluble solids variables is negligible. We tentatively identified 13 volatile compounds in fresh fruit and pulp, ethyl acetate, ethyl hexanoate, and linalool being the volatiles with the highest area percentage in the two products.The esters were predominant in both the fruit and strawberry pulp. Time is the most determining factor in modifying the strawberry pulp volatile profile, having an isolated effect on the increase of ethanol, ethyl butanoate, and linalool. Practical applicationsThe strawberry is very used worldwide as raw material to different products, due to its color, flavor, and aroma. Thus, obtaining further information about the changes caused by processing and storage is of great importance for the food industry. This study shows the effect of simultaneous application of different processing techniques (pasteurization and freezing methods) on physicochemical variables and volatile profile of strawberry pulp over prolonged storage. Significant and unpublished results involving color, pH, acidity, soluble solids, and volatile compounds of strawberry frozen pulp over storage period are presented and may be applied for food industry to keep the pulp quality.