NaCl treatment with LDPE packaging is an effective method to maintain appearance and regulating flavor qualities of fresh-cut apples

NaCl is regarded as a low cost and effective anti-browning agent for fresh-cut apples, but is rare discussed on keeping flavor.

In this study, the anti-browning effect of 0.1 mol/L NaCl with low density polyethylene (LDPE) packaging bags for apple was verified by lower browning degree, the total phenolic content, polyphenol oxidase (PPO), phenylalanine ammonia lyase (PAL) activity and relative genes expression.

The browning score and flavor assessment of fresh-cut apples with NaCl treatment was 1.49 and 1.47 times that of control on the 12th d, which showed NaCl treatment increased the business value of fresh-cut apples.

Butanoic acid methyl ester, butanoic acid 2-methyl-, methyl ester and hexanoic acid methyl ester were markedly higher in NaCl-treated slices than the control.

In addition, the linoleic acid content increased with NaCl treatment, which was 2.3 times that of the control on the 12th day. Enzyme activities and relative genes expression in lipoxygenase (LOX) pathway including LOX, ethanol dehydrogenase (ADH), and alcoholacyltransferase (AAT) were activated in apple slices with NaCl treatment.

Among them, AAT1 expression changed the most, eight times that of the control on day 1. However, the activity and relative expression of pyruvate decarboxylase (PDC) related to ethanol synthesis were inhibited.

Moreover, NaCl enhanced β-glucosidase (BGL) activity of fresh-cut apples by 1.9 times on day 1 and its concentration in the reaction system was proportional to the BGL activity.

The results indicate NaCl treatment with LDPE packaging is an effective method to maintain appearance and regulating flavor qualities of fresh-cut apples. 

Sources

NACL TREATMENT WITH LOW-DENSITY POLYETHYLENE PACKAGING BAGS CAN ENHANCE AROMA OF FRESH-CUT APPLE, NOT ONLY INHIBIT ITS BROWNING 
Jingying Shi, Su Ma, Qingguo Wang 
5th International Conference on Fresh-Cut Produce: Maintaining Quality and Safety, Foggia (Italy), 3-6 June 2024