Optimization of water curing for the preservation of chestnuts (Castanea sativa Mill.) and evaluation of microbial dynamics during process

Food Microbiol. 2014 Sep:42:47-55. doi: 10.1016/j.fm.2014.02.009. Epub 2014 Feb 22.

Abstract

Chestnuts are very perishable fruits, whose quality may be compromised during postharvest handling. Damage can be caused both by insects and fungi. Water curing, a commonly used postharvest method, is based on soaking fruits in water typically for about one week. Factors that affect effectiveness of water curing have only been explained partially. A decrease in pH, likely imputable to a light fermentation caused by lactic acid bacteria, may inhibit the growth of moulds. In this study a Lactobacillus pentosus strain was selected for its ability to inhibit fungi, and used as a starter culture during water curing. As second goal, a reduction of the environmental impact of the process was evaluated by using water that had been re-cycled from a previous curing treatment. Experiments were performed on pilot as well as on farm scale. In all trials, microbial dynamics were evaluated by means of a polyphasic approach including conventional and molecular-based analyses. According to results, the employment of an adjunct culture appears as a very promising opportunity. Even if no reduction in the duration of the process was achieved, waters exhibited a minor microbial complexity and fruits did not lose the natural lustre after the process.

Keywords: Chestnuts; Lactobacillus pentosus; PCR-DGGE; Penicillium spp.; Water curing.

Publication types

  • Evaluation Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Antibiosis
  • Biodiversity
  • Fagaceae / chemistry
  • Fagaceae / microbiology*
  • Food Contamination / analysis
  • Food Contamination / prevention & control
  • Food Preservation / instrumentation
  • Food Preservation / methods*
  • Fruit / chemistry
  • Fruit / microbiology
  • Fungi / classification
  • Fungi / genetics
  • Fungi / isolation & purification
  • Fungi / physiology
  • Hydrogen-Ion Concentration
  • Lactobacillus / physiology
  • Water / chemistry*

Substances

  • Water