Interactions of Pre- And Postharvest Influences on Fruit and Vegetable Quality as Basic Decision for Chain Management

Abstract

For developing a quality chain management of horticultural products radish bulbs and pepino fruits were chosen as model products. In a first attempt the interaction of some of the most important preharvest influences, the climate effect and the ripening stage at harvest, and different postharvest effects, such as packaging, coatings, CA storage were investigated in respect to the product's precondition at harvest. The investigations of radish indicated that the preharvest dependency of quality determining compounds ranged from a slight climate influence, over a moderate climate effect up to a strongly distinctive climate influence and also effect postharvest behavior. Moreover, it is demonstrated that the quality preserving effect of packaging materials and coatings depends on the precondition of radishes being influenced by the seasonal preharvest conditions. Considering sensory and anticancerogenic aspects, OPP-Coex-film packaging might be recommended due to a beneficial effect on pectic substances and alkenyl glucosinolates in radish grown in summer and autumn. However, starch coated radishes showed highest contents of fructose and glucose. Depending on the ripening stage different postharvest treatments were beneficial in preserving pepino quality. In mature pepino fruits packaging and coating resulted in the maintenance of the sensory, antioxidative and anticancerogenic potentials, while ripe pepino fruits maintained their quality at 5 °C storage temperature. Enhanced CO 2 concentrations up to 20% led tendentiously to a reduction of bioactive pigments. Concluding from these investigations the development of a chain management implies the consideration of the product's precondition at harvest as a result of external and internal influences on the product metabolism for choosing suitable, quality maintaining postharvest treatments.

Genotypic effects on glucosinolates and sensory properties of broccoli and cauliflower

“…This corresponds to the literature, which show a slightly higher fructose or glucose proportion depending on cultivation period and place [35,[43][44][45]. The sucrose proportion was low with 5 up to 8% in green, purple and Chinese broccoli as well as in purple cauliflower.…”

“…Rosa et al [8] also observed this phenomenon during a late planting season in Portugal when temperatures were relative low; however, during the summer season when daily mean temperatures were A 20 8C, the contents among the cultivars did not differ in his investigations and were very low. Taking into consideration the data here and those from several other investigations [35], we can conclude that the broccoli cultivar choice can influence the level of health-relevant glucoraphanin content (preliminary step of sulforaphan) when grown between 14 and 18 8C.…”

“…In 1998, the low daily mean temperatures resulted in the entire glucosinolate content of all broccoli and cauliflower cultivars increasing by an average of 188% compared to averages from 1999 and 2000 which both had higher daily mean temperatures. Experiments with broccoli also show the same results with differing daily mean temperatures and PAR levels during production periods compared over several years [35]. Rosa et al [18] explain the influence of temperature on the glucosinolate level with increasing myrosinase activity at higher daily mean temperatures, which would mean increased glucosinolate degradation.…”

Glucosinolates in Mixed-Packaged Mini Broccoli and Mini Cauliflower under Modified Atmosphere

“…Moreover, the differences in postharvest glucosinolate metabolism of mini broccoli and mini cauliflower as well as the different responses to altered gas composition of broccoli are assumed to be due to the vegetables' precondition being influenced by the seasonal preharvest conditions and the development stage at harvest as was found for radish (36). The various products' precondition can be demonstrated by variable glucosinolate content at harvest.…”