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Highlights • Oxalic acid treatments affect the quality properties of green and purple asparagus. • Cold storage and OA affected the overall appearance and the cut end-dehydration. • Rutin, feruloyl and cumaroyl quinic acids were detected in Grande and Vegalim spears. • Cyanidin rutinoside was the most represented anthocyanin in Purple Passion cultivar. • A sensor-biosensor system was used to measure antioxidant activity and ascorbic acid. Abstract The effect of oxalic acid (OA) treatment on visual properties and bioactive compounds of two green and one purple cultivars of fresh asparagus was investigated during twelve storage days at 5 °C. Cold storage and OA treatment positively affected the overall appearance of the investigated cultivars. Cut-end dehydration increased, all along the storage period, in all cultivars but, the negative effect of the storage, clear on control samples, was mitigated by OA. The most represented compounds in Grande and Vegalim cultivars were: quercetin rutinoside, feruloyl quinic acid and cumaroyl quinic acid. Cyanidin glucosyl rutinoside, cyaniding rutinoside and peonidin rutinoside were identified in Purple Passion cultivar. The bioactive compounds seemed to be affected by storage but not by OA treatment. The sensor-biosensor system indicated that the antioxidant activity is negatively affected by storage but not by OA. The decrease of antioxidant activity coincided with the reduction of ascorbic acid levels in all the cultivars. [ABSTRACT FROM AUTHOR]

Table grapes (cv. Italia) were stored at 5 °C in air or in modified atmosphere with low O 2 (1%) and low (0.03–10%) or high (>20%) CO 2 . Volatile organic compounds (VOCs) associated with quality (respiration rate, acetaldehyde and ethanol, water status of rachis) and sensory parameters (visual quality, rachis browning, characteristic odour and flavour, off-odour and off-flavour) were evaluated. Low CO 2 preserved the quality and sensory parameters, whereas high CO 2 caused a fermentative metabolism. A total of 126 VOCs were identified by HS-SPME/GC–MS analysis. Principal component analysis (PCA) identified ( Z )-2-hexenal and (E,Z)-2,4-hexadienal as potential marker of freshness; whereas, acetaldehyde, ethanol, 1-butanol, 3-methyl-1-butanol, 1-octanol and 1-nonanol were correlated to fermentation processes. Partial least-square regression analysis (PLSR) was used to identify (R 2 = 0.95) the main predictors of off-odour as ethanol and ethyl acetate (+) and hexanal and β-linalool (−). [ABSTRACT FROM AUTHOR]

The preservation of the freshness of fruits and vegetables until their consumption is the aim of many research activities. Quality losses of fresh fruit and vegetables during cold chain are frequently attributable to an inappropriate use of postharvest technologies. Moreover, especially when fresh produce is transported to distant markets, it is necessary to adopt proper postharvest preservation technologies in order to preserve the initial quality and limit microbial decay. Nowadays, for each step of supply chain (packing house, cold storage rooms, precooling center, refrigerate transport and distribution), are available innovative preservation technologies that, alone or in combination, could improve the fresh products in order to maintain the principal quality and nutritional characteristics. The issue groups five original studies and two comprehensive reviews within the topic of preservation technologies related to innovative packaging and postharvest operation and treatments, highlighting their effect on quality keeping. [ABSTRACT FROM AUTHOR]

This study evaluated the respiration rate of coated and uncoated (control) papayas (Carica papaya L.) with 15% of Kelulut honey (KH) nanoparticles (Nps) coating solution during cold storage at 12 ± 1 °C for 21 days. The respiration rate of the papayas significantly changed during storage, with an increase in CO2 and a decrease in O2 and C2H4, while the ascorbic acid and total phenolic content was maintained. The changes in respiration rate were rather slower for coated papayas when compared to control ones. A kinetic model was established from the experimental data to describe the changes of O2, CO2, and C2H4 production in papayas throughout the storage period. All O2, CO2, and C2H4 were experimentally retrieved from a closed system method and then represented by the Peleg model. The outcomes indicated the Peleg constant K1 and K2, which were gained from linear regression analysis and coefficients of determination (R2), seemed to fit well with the experimental data, whereby the R2 values exceeded 0.85 for both coated and control papayas. The model confirmed both the capability and predictability aspects of the respiration rate displayed by papayas coated with KH Nps throughout the cold storage period. This is supported by the differences in the stomatal aperture of coated and control papaya shown by microstructural images. [ABSTRACT FROM AUTHOR]

The volatile profile of two hybrids of “Radicchio di Chioggia”, Corelli and Botticelli, stored in air or passive modified atmosphere (MAP) during 12 days of cold storage, was monitored by solid phase micro-extraction (SPME) GC–MS. Botticelli samples were also subjected to sensory analysis. Totally, 61 volatile organic compounds (VOCs) were identified in the headspace of radicchio samples. Principal component analysis (PCA) showed that fresh product possessed a metabolic content similar to that of the MAP samples after 5 and 8 days of storage. Projection to latent structures by partial least squares (PLS) regression analysis showed the volatiles content of the samples varied depending only on the packaging conditions. Specifically, 12 metabolites describing the time evolution and explaining the effects of the different storage conditions were highlighted. Finally, a PCA analysis revealed that VOCs profile significantly correlated with sensory attributes. [ABSTRACT FROM AUTHOR]