Effect of Different Modified Atmosphere Packaging on the Quality of Mulberry Fruit (Morus alba L. cv Kokuso 21)

Phytochemical and functional characterization of cultivated varieties of Morus alba L. fruits grown in Italy

Morus alba L. fruits are considered functional foods with an important nutritional value for their high content of polyphenols. Therefore, the type and level of phytochemicals of the soroses from 13 M. alba cultivars grown in Italy were characterized due to the lack of data available about their nutraceutical properties. Mature M. alba fruits exhibited variable polyphenol, flavonoid, anthocyanin, proanthocyanins, and 1-deoxynojirimycin contents which resulted in different antioxidant and α-glucosidase inhibitory activities. Regression models built on UHPLC-HRMS results revealed a strong correlation between the expression of quercetin derivatives, cyanidin 3-O-glucoside, caffeoyl methyl quinates, and 5,5'-dehydrodivanillic acid, and the biological activity of each fruit. On another note, principal component analysis revealed that the quantity of caffeoyl/dicaffeoyl methyl quinate, caffeoylquinic acids, and quercetin derivatives decreased during ripening. The results on the compositional and functional characterization of mature M. alba fruits might improve their consumption and economic value in Italy.

The Darker the Better: Identification of Chemotype Profile in Soroses of Local and Introduced Mulberry Varieties with Respect to the Colour Type

Mulberries are the "essence of the past", the so-called Proust effect, for the inhabitants of the sericultural regions who enthusiastically remember feeding silkworms with mulberry leaves and picking the different coloured fruits that were their favourite sweets in childhood. To determine the chemistry behind the colour and taste of mulberry soroses, the main metabolites of the local and introduced varieties were studied. The soroses were classified into five different colour types and the size parameters were determined. The main sugars identified were glucose and fructose, while the predominant organic acids were citric and malic acids, which were highest in the darker varieties, and fumaric and tartaric acids, which were highest in the lighter varieties. A total of 42 phenolic compounds were identified. The predominant phenolic acid was chlorogenic acid, followed by other caffeoylquinic acids and coumaroylquinic acids. The predominant anthocyanins were cyanidin-3-glucoside and cyanidin-3-rutinoside. According to PCA analysis, the colour types showed a clear chemotype character. The sweet taste of the yellowish-white soroses was defined by 49% fructose, followed by 45% glucose and 6% organic acids. The sour character of the black genotypes was characterised by a lower sugar and higher (11%) organic acid content. The colour- and species-dependent effect was observed in the proportion of caffeoylquinic acids and quercetin glycosides, which decreased with increasing colour intensity from 60% of the total to 7%, and from 17% to 1%, respectively. An upward trend was observed for flavanols (5% to 29%) and anthocyanins, which accounted for 62% of the total phenolics in black varieties. This article gives an insight into the metabolite composition of mulberry soroses as the sweets of choice between light and sweet and dark and sour.

Effects of Argon-Based and Nitrogen-Based Modified Atmosphere Packaging Technology on the Quality of Pomegranate (Punica granatum L. cv. Wonderful) Arils

Ready-to-eat pomegranate arils are considered a “functional food” for their health benefits and have desirable sensory characteristics, which have caused an increasing interest by the consumers for this product. The preparation process of ready-to-eat fruit products can cause severe injuries and worsen their quality and shelf life significantly. Modified atmosphere packaging (MAP) has been used broadly in the last years to maintain the quality of processed fruits and showed optimal results, in spite of the possible problems caused by the depletion of O₂ and corresponding accumulation of CO₂ in the package. This study was conducted to evaluate the effects of different MAP treatments, based on nitrogen or alternatively on a noble gas, argon, in combination with refrigerated storage (0, 4, 8, 12, and 16 days at 4 ± 1 °C and 90 ± 5% RH) on the qualitative parameters of pomegranate arils with the aim to prolong their post-harvest life maintaining the original quality. The argon-based MAP treatment (MAPAr) was the one that provided the best results, assuring a limited loss of weight and juice content. The use of noble gas allowed to maintain a high sugar/acid ratio until 16 days from packaging. Sensory analysis on all MAP treated arils and, on the juice, obtained from them were carried out, and judges showed a preference for MAPAr treated arils and juice until day 12 from packaging.