Effect of temperature and relative humidity during transportation on green coffee bean moisture content and ochratoxin A production.

Changes in temperature, relative humidity, and moisture content of green coffee beans were monitored during transportation of coffee from Brazil to Italy. Six containers (three conventional and three prototype) were stowed in three different places (hold, first floor, and deck) on the ship. Each prototype was located next to a conventional container. The moisture content of the coffee in the container located on the first floor was less affected by environmental variations (0.7%) than that in the hold and on the deck. Coffee located in the hold showed the highest variation in moisture content (3%); in addition, the container showed visible condensation. Coffee transported on the deck showed an intermediary variation in moisture (2%), and there was no visible condensation. The variation in coffee moisture content of the prototype containers was similar to that of the conventional ones, especially in the top layers of coffee bags (2 to 3%), while the increase in water activity was 0.70. This suggests that diffusion of moisture occurs very slowly inside the cargo and that there are thus sufficient time and conditions for fungal growth. The regions of the container near the wall and ceiling are susceptible to condensation since they are close to the headspace with its high relative humidity. Ochratoxin A production occurred in coffee located at the top of the container on the deck and in the wet bags from the hold (those found to be wet on opening the containers at the final destination).

Carbohydrate metabolism as related to high-temperature conditioning and peel disorders occurring during storage of citrus fruit.

The aim of this research was to understand the involvement of the carbohydrate metabolism in physiological disorders occurring during the postharvest storage of citrus fruit. These disorders, manifested in the rind, depreciate fruit quality and often originate important losses. There has been increasing interest in the use of nonharmful treatments, such as high-temperature conditioning, to avoid citrus peel damage during fruit storage at low temperature in chilling-sensitive cultivars, but their influence in postharvest disorders occurring at nonchilling temperatures and the mechanisms related to them are poorly understood. The data obtained showed that heat conditioning (3 days/37 degrees C) increases the chilling tolerance of cv. Navelate fruit and favored sucrose, but not hexoses, accumulation and its maintenance after the fruit was transferred to low temperature. This effect was related to heat-induced increase in the activities of the sucrose-synthesizing enzymes sucrose phosphate synthase (SPS) and sucrose synthase (SS). Furthermore, sucrose levels and the activities of both enzymes were higher in cv. Pinalate oranges, a chilling-tolerant spontaneous abscisic acid deficient mutant of Navelate. In contrast, carbohydrates appeared not to be involved in the susceptibility of oranges to rind staining, a physiological disorder different from chilling injury, which mainly occurred at a nonchilling temperature (12 degrees C) and was not reduced by heat conditioning. The effect of low temperature in SS and SPS activities was less than that of high temperature, which might be related to the lower changes occurring in sucrose during fruit storage at 2 degrees C.

Efeito da trituração e imersão em água na redução dos compostos cianogênicos do albedo de maracujá amarelo / Effect of grinding and soaking on the reduction of cyanogenic compounds in the albedo of yellow passion fruit

A importância dos compostos funcionais presentes em alguns resíduos vegetais tem ampliado as pesquisas para viabilizar seu aproveitamento na alimentação humana. O Brasil é o maior produtor mundial de maracujá, principalmente do amarelo (Passiflora edulis Sims f. flavicarpa Degener), com produção de aproximadamente 478 mil toneladas anuais, utilizados principalmente para o consumo "in natura" e fabricação de suco. O albedo corresponde de 12% a 32% da massa do maracujá amarelo maduro, contendo, em base seca, cerca de 20% de pectina (fibra solúvel), mas também compostos cianogênicos, como a prunasina, amigdalina e sambunigrina. Este trabalho teve o objetivo de avaliar o efeito da trituração e da imersão em água na redução dos compostos cianogênicos do albedo de maracujá amarelo. Foram utilizdos frutos de maracujá amarelo maduros obtidos de produtor comercial, com pelo menos 85% da casca com cor amarela. O efeito da trituração foi estudado utilizando-se três tamanhos de partícula e o efeito da imersão do albedo em água (proporção 1:3) foi avaliado por seis dias (144h) em condição ambiente (temperatura média de 28,5ºC). Foram analisados os teores de compostos cianogênicos totais (CCT), glicosídeos cianogênicos (GC) e compostos cianogênicos não glicosídeos (CCNG). O processo de imersão dos albedos em água provocou a perda de parte dos glicosídeos cianogênicos, entretanto, apesar do efeito significativo do tempo de imersão, os teores remanescentes de CCT e GC mantiveram-se elevados. Nas condições deste experimento, observou-se baixa ação dos microorganismos contaminantes e praticamente ausência de ação de enzimas endógenas na degradação dos glicosídeos cianogênicos durante todo o peíodo de imersão, independetemente do tamanho da partícula do albedo...