The Effect of Organic Acid Pretreatment and Modified Atmosphere on Shelf Life of Dry Coleslaw Mix

Abstract

The aim of the study was to determine the effect of soaking in ascorbic acid and citric acid solution and modified atmosphere packaging on the quality of a coleslaw mix stored for 12 days at 4C. Pretreatment caused a reduction by ∼2 logarithmic cycles for counts of psychrophilic bacteria from the genus Pseudomonas, and mesophilic yeasts, as well as a significant decrease in the counts of mesophilic bacteria and coliform bacteria. Packaging of tested samples in modified atmosphere with high contents of oxygen (70 or 50%) and carbon dioxide (30%) caused an inhibition of growth for mesophilic, psychrophilic, lactic acid and coliform bacteria during storage. Application of atmosphere with increased contents of CO2 (25 or 30%) resulted in the inhibition of growth of bacteria from the genus Pseudomonas, while in the case of elevated (70%) or reduced contents of oxygen (5%) a slower growth of yeasts was observed. Practical Application The using of the atmosphere with a high content of oxygen is the new trend in the minimal processing of fruits and vegetables. When applying atmosphere with a high oxygen content in packaging of fruit and vegetables it is recommended to use barrier films, which guarantees maintenance of high contents of this gas during product storage. In the case of coleslaw mix, sensory quality (particularly aroma) is not acceptable. Using pretreatment (soaking in ascorbic acid (5 g/L) and citric acid (5 g/L) solution) and atmosphere of 70% O2 and 30% CO2 with microperforated barrier film results in good sensory and microbiological quality (regarding to research parameters) of the coleslaw mix during 12 days of storage.