The drying of grapes is a more complex process compared to the dehydration of other agricultural materials due to the necessity of a pretreatment operation prior to drying. Grape drying to produce raisins is a very sl...The drying of grapes is a more complex process compared to the dehydration of other agricultural materials due to the necessity of a pretreatment operation prior to drying. Grape drying to produce raisins is a very slow process, due to the peculiar structure of grape peel, that is covered by a waxy layer. Its removal has been so far carried out by using several chemical pre-treatments. However, they cause heterogeneity in the waxes removal and create microscopic cracks. In this paper an abrasive pretreatment for enhancing the drying rate and preserving the grape samples is proposed. Two cultivars of grape were investigated: Regina white grape and Red Globe red grape. The drying kinetics of untreated and treated samples were studied using a convective oven at 50°C. Fruit quality parameters such as sugar and organic acid contents, shrinkage, texture, peel damage (i.e. by SEM analysis) and rehydration capacity were studied to evaluate the effectiveness of abrasive pretreatment on raisins. Abrasive pretreatment contributed to reduce drying time and rehydration time. The treated and untreated dried grapes were significantly different (p < 0.05) in sugar and in tartaric acid content. On the contrary, no significant differences (p < 0.05) in malic and citric acids and in texture properties between untreated and treated samples were observed.展开更多
Compost, rich in plant nutrients, is a readily available fertilizer with beneficial effects on physical, chemical, biochemical and biological properties of the soils. Moreover compost-based treatments can exert protec...Compost, rich in plant nutrients, is a readily available fertilizer with beneficial effects on physical, chemical, biochemical and biological properties of the soils. Moreover compost-based treatments can exert protective effects against plant diseases occurrence and/or stimulate an enhanced plant physiological status with improvements in quantity and quality of crop productions. In this study the effects of three different compost-based cropping managements on the productive response and main quality parameters of watermelon fruits were investigated. Treatments, in comparison with the conventional cultivation method, were: soil amendment with an agricultural waste compost (AWC), a municipal waste compost (MWC) and a foliar treatment with a compost tea blend (CTB). The productive responses and colour parameters related to compost treatments did not show significant differences compared to control ones, which reached a total yield of about 10.22 kg·m-2 with a mean weight of 2.74 kg. AWC caused a higher ascorbic acid content with an increase of 50% than conventional treatment, while fruits obtained by CTB showed higher values in firmness and Quality Index than control samples. The analysis of main sugars highlighted that the application of compost as biofertilizer influenced the ratio among fructose, glucose and sucrose with respect to those observed for control fruits.展开更多
文摘The drying of grapes is a more complex process compared to the dehydration of other agricultural materials due to the necessity of a pretreatment operation prior to drying. Grape drying to produce raisins is a very slow process, due to the peculiar structure of grape peel, that is covered by a waxy layer. Its removal has been so far carried out by using several chemical pre-treatments. However, they cause heterogeneity in the waxes removal and create microscopic cracks. In this paper an abrasive pretreatment for enhancing the drying rate and preserving the grape samples is proposed. Two cultivars of grape were investigated: Regina white grape and Red Globe red grape. The drying kinetics of untreated and treated samples were studied using a convective oven at 50°C. Fruit quality parameters such as sugar and organic acid contents, shrinkage, texture, peel damage (i.e. by SEM analysis) and rehydration capacity were studied to evaluate the effectiveness of abrasive pretreatment on raisins. Abrasive pretreatment contributed to reduce drying time and rehydration time. The treated and untreated dried grapes were significantly different (p < 0.05) in sugar and in tartaric acid content. On the contrary, no significant differences (p < 0.05) in malic and citric acids and in texture properties between untreated and treated samples were observed.
文摘Compost, rich in plant nutrients, is a readily available fertilizer with beneficial effects on physical, chemical, biochemical and biological properties of the soils. Moreover compost-based treatments can exert protective effects against plant diseases occurrence and/or stimulate an enhanced plant physiological status with improvements in quantity and quality of crop productions. In this study the effects of three different compost-based cropping managements on the productive response and main quality parameters of watermelon fruits were investigated. Treatments, in comparison with the conventional cultivation method, were: soil amendment with an agricultural waste compost (AWC), a municipal waste compost (MWC) and a foliar treatment with a compost tea blend (CTB). The productive responses and colour parameters related to compost treatments did not show significant differences compared to control ones, which reached a total yield of about 10.22 kg·m-2 with a mean weight of 2.74 kg. AWC caused a higher ascorbic acid content with an increase of 50% than conventional treatment, while fruits obtained by CTB showed higher values in firmness and Quality Index than control samples. The analysis of main sugars highlighted that the application of compost as biofertilizer influenced the ratio among fructose, glucose and sucrose with respect to those observed for control fruits.
