Modified Atmosphere Packaging of Kabaaşı Apricot (Prunus armeniaca L. ‘Kabaaşı’): Effect of Atmosphere, Packaging Material Type and Coating on the Physicochemical Properties and Sensory Quality

Improving the storage quality and suppressing off-flavor generation of winter jujube by precise micro-perforated MAP

Introduction

Traditional modified atmosphere packaging (MAP) cannot meet the preservation requirements of winter jujube, and the high respiration rate characteristics of winter jujube will produce an atmosphere component with high CO2 concentration in traditional MAP. Micro-perforated MAP is suitable for the preservation of winter jujube due to its high permeability, which can effectively remove excess CO2 and supply O2. In this study, a microporous film preservation system that can be quickly applied to winter jujube was developed, namely PMP-MAP (precise micro-perforated modified atmosphere packaging). An experiment was designed to store winter jujube in PMP-MAP at 20°C and 2°C, respectively. The quality, aroma and antioxidant capacity, etc. of winter jujube at the storage time were determined.

Methods

In this study, the optimal micropore area required for microporous film packaging at different temperatures is first determined. To ensure the best perforation effect, the effects of various factors on perforation efficiency were studied. The gas composition within the package was predicted using the gas prediction equation to ensure that the gas composition of the perforated package achieved the desired target. Finally, storage experiments were designed to determine the quality index of winter jujube, including firmness, total soluble solids, titratable acid, reddening, and decay incidence. In addition, sensory evaluation, aroma and antioxidant capacity were also determined. Finally, the preservation effect of PMP-MAP for winter jujube was evaluated by combining the above indicators.

Results and discussion

At the end of storage, PMP-MAP reduced the respiration rate of winter jujube, which contributed to the preservation of high total soluble solids and titratable acid levels, and delayed the reddening and decay rate of winter jujube. In addition, PMP-MAP maintained the antioxidant capacity and flavor of winter jujube while inhibiting the occurrence of alcoholic fermentation and off-flavors. This can be attributed to the effective gas exchange facilitated by PMP-MAP, thereby preventing anaerobic stress and quality degradation. Therefore, the PMP-MAP approach is an efficient method for the storage of winter jujube.

Evaluation of a Packaging System in Pallets Under Modified Atmosphere to Extend the Shelf-life of ‘Padrón’ Peppers Stored at Refrigeration Temperature

A modified atmosphere packaging (MAP) system in pallets was developed for ‘Padrón’ peppers as a way to extend their shelf-life while maintaining good fruit quality. Peppers were stored at 6 °C in cardboard boxes arranged on pallets wrapped in micro-perforated low-density polyethylene (LDPE) bags. Physico-chemical (moisture, firmness, color, chlorophylls, carotenoids, ascorbic acid, and total phenolic content) and sensory analysis were carried out after 0, 7, 14, and 21 days of storage. An initial mixture of 11.8% O2–8.5% CO2 prevented anaerobic conditions and kept suitable CO2 levels throughout the entire storage period. Silica gel was tested as a moisture absorbent and considerably reduced water vapor condensation inside packaging bags. The MAP system developed maintained the shelf-life of peppers until the end of the 21-day storage period. The fruit always showed a good appearance and color. No rotting or other types of undesirable alterations were observed. MAP markedly reduced the fraction of peppers with water loss as evidenced by a minimum percentage of fruit with wrinkles (12.5%) as compared to unpackaged samples (75%). Good pigment stability was also observed.

Eating quality and health-promoting properties of two sweet cherry (Prunus avium L.) cultivars stored in passive modified atmosphere

Two sweet cherry cultivars (‘New Star’ and ‘Sweet Heart’) were chosen to explore the impact of passive modified atmosphere packaging on the eating quality and health-promoting properties of fruit. Packaged and unpackaged fruits were stored at 0 ℃ for 15 or 30 days, followed by zero or three days at 20 ℃, after which the analyses were undertaken. In most cases, modified atmosphere packaging helped preserving higher firmness values and reducing the incidence of alterations and decay in both cultivars, but the effects on other physicochemical attributes were different for each cultivar. Partial least squares regression procedures were used to reveal relationships among the different variables assessed. Generally, fruits displaying higher antioxidant capacity were also characterised by higher values for firmness and titratable acidity, in turn related to better acceptability scores in both cultivars. However, the attributes contributing most to acceptability were different in each case. In ‘New Star’ fruit, acceptability was closely related to the perception of cherry flavour. In this cultivar, acetaldehyde content was related to the perception of off-flavours, while ethanol content was found to associate to soluble solids and to the perception of sweetness. In contrast, acceptability of ‘Sweet Heart’ fruit was related mainly to the perception of firmness and, to a lower extent, of sweetness.