Volatile Compounds and Quality Characteristics of Fresh-Cut Apples and Mixed Fruits Coated with Ascorbic Acid during Cold Storage

Abstract

Fresh-cut apples are commonly known as minimally processed agricultural products because of their convenience and ease of consumption. However, during storage, the quality of the apple rapidly changes after cutting due to enzymatic and non-enzymatic processes. This study aimed to monitor the quality changes and volatile compounds in fresh-cut apples at various temperatures using an electronic nose. The quality relationships of the product during distribution and storage using cold chain systems were also evaluated. The results showed that the total viable count initially differed between fresh-cut apples (2.59 Log CFU/g) and mixed fruits (apple ‘Hongro’, kumquat, and cherry tomatoes) (3.2 Log CFU/g) during the storage period (p < 0.05). There were no significant differences (p > 0.05) in the physicochemical properties except for the firmness, color values, browning index, whiteness index, and titratable acidity. The volatile compounds found in fresh-cut apples indicating apple fruit aroma were propyl propanoate and ethyl isovalerate, hexanol (freshness), and methanethiol and ethyl acetate (unpleasant off-odor), and these compounds could be used as markers for the deterioration process in fresh-cut apples during storage. Methanethiol and ethyl acetate were correlated with microbial growth (Pearson correlation of 0.81–0.98 for total viable microbe and 0.49–0.90 for coliform count). The limonene level was higher in the mixed fruits than in other treatments and gradually increased during storage due to the kumquat.

Enhancing Fresh-Cut Apple Preservation: Impact of Slightly Acidic Electrolyzed Water and Chitosan–Apple Essence Microencapsulation Coating on Browning and Flavor

“…To comprehensively assess the impact of microencapsulation synergistic treatments on the odor changes of fresh-cut apples, we compiled the response value data from all sensors and conducted a comparative analysis of the trends in total response values (as shown in Figure 6c). In the control group, the response values of the electronic nose steadily increased with storage time, possibly due to the increased production of volatile compounds resulting from respiration and other physiological activities of fresh-cut apples during storage [7,30]. The AEM treatment effectively enhanced the flavor of fresh-cut apples, especially during the mid-storage period.…”