Influence of fruit treatments on perishability during cold storage of sweet chestnuts

Abstract

With a view to enhancing the quality of local chestnut in southern Switzerland, the impact of three treatments ['soaking', 'cold bath' (hydrotherapy) and 'warm bath' (thermo-hydrotherapy)] on the qualitative, chemical and sensory characteristics of the nuts during 90 days of cold storage was evaluated. Weight and water content decreased significantly with increasing duration of storage. Starch content decreased following a negative logistic trend. Sucrose, however, increased steeply according to a monomolecular trend and was significantly higher between 0 and 60 days of storage in the soaked chestnuts than in the cold-bath treated nuts. The mean proportion of mouldy fruit remained constant at 27% for the warm-bath treated nuts and increased from 16 to 30% for the cold-bath treated fruit and from 28 to 63% for the soaked nuts during the 90 days of cold storage. The most frequently isolated moulds were Ciboria batschiana, Penicillium spp. and Mucor hiemalis. Warm and cold baths were successful in eliminating the larvae of Cydia splendana but the cold bath was inadequate to control Curculio elephas. Cold bath significantly reduced the sensory qualities (sweetness, aroma, texture) of the nuts, but made them easier to peel, as did the warm bath.

Effects of gamma and electron beam irradiations on the triacylglycerol profile of fresh and stored Castanea sativa Miller samples

“…Furthermore, chemical fumigation is harmful to the human health and to the environment (UNEP, 2006), while heat treatments do not prevent mold growth (Jermini et al, 2006). Quality requirements demand enhanced conservation techniques for chestnuts and related products.…”

Efficacy of washing treatments in the reduction of post-harvest decay of chestnuts (Castanea crenata ‘Tsukuba’) during storage

“…That study and another study (Washington et al 1997) also showed that microbial populations were much higher on the shells (pericarps) compared with the kernels. Molds are reported as the most prominent post-harvest, decay agents for chestnut (both shells and kernels) (Jermini et al 2006; Donis-González 2008). However, it is possible that some microbes associated with shells and kernels of chestnut might be antagonistic to decay-causing microbes.…”

“…In addition, improved post-harvest storage of chestnuts can provide potential economic benefits by reducing spoilage and extending the marketing period. Nonetheless, storageassociated spoilage of chestnuts represents a major postharvest problem for chestnut marketing, and fungi have been identified as the major cause of chestnut rots (Overy et al 2003;Jermini et al 2006;Donis-González 2008). Infection of the fruits by spoilage agents usually occurs after the chestnuts fall to the ground and are exposed to soil, plant matter, and (or) dirty water during the harvest (Mencarelli 2001;Kader 2003).…”

Sweet chestnut cultures in the Southern Alps – conservation and regional development

“…This was the only way of achieving a harvest volume worth marketing. In both regions, new methods of treatment, such as thermo-hydrotherapy and cold storage are put to the test in order to preserve the fruits to modern quality levels (Bounous 2002;Jermini et al 2006). The chestnuts are subjected to modern standards of marketing -which means that quality, homogeneity and an effective distribution chain are becoming ever more important.…”