Shelf life of fresh-cut spinach as affected by chemical treatment and type of packaging film

Abstract

Abstract - Fresh-cut vegetables are an important and rapidly developing class of convenience foods. Theirstorage life may be greatly reduced due to their high rates of respiration and transpiration and the possibilityof enzymatic and microbiological deterioration. Consequently, the objective of this work was to determine theshelf life and the failure attribute that conditioned the shelf life of fresh-cut spinach treated with chemicalsolutions and packaged in bags with different permeabilities. The shelf life of fresh-cut vegetables wasdefined as the time of refrigerated storage at which any one of the sensory attributes scored below 7 or whenthe microbiological counts exceeded 5.10 7 CFU/g. Fresh-cut spinach was treated with citric acid and ascorbicacid solutions and packaged in mono-oriented polypropylene (OPP) bags or low-density polyethylene (LDPE)bags. Sensory attributes and total microbial counts were evaluated throughout refrigerated storage. Responsesurface methodology (RSM) was used to study the simultaneous effect of chemical treatment and refrigeratedstorage time on sensory and microbiological quality of fresh-cut spinach. A quadratic polynomial regressionmodel was assumed for predicting off-odor, general appearance, wilting, browning, color, and mesophilicaerobic population. Type of packaging film only influenced development of off-odor (p≤0.001) and had noeffect on visual sensory attributes or microbiological counts (p>0.05). Development of off-odor was theattribute that limited shelf life of fresh-cut spinach packaged in OPP bags. On the other hand, shelf life ofsamples packaged in LDPE bags was dependent on a decrease in general appearance or an increase inmicrobiological counts, depending on the chemical treatment used.