Application of an Eco-Friendly Antifungal Active Package to Extend the Shelf Life of Fresh Red Raspberry (Rubus idaeus L. cv. ‘Kweli’)

The main objective of this study was to extend the shelf life of fresh red raspberry (Rubus idaeus. L. cv. ‘Kweli’) by using active film-pads inside commercial compostable packages. The pads were produced with chitosan (Ch) with the incorporation of green tea (GTE) and rosemary (RSME) ethanolic extracts as natural antifungal agents. Pads were placed on the bottom of commercial fruit trays underneath the fruits, and the trays were heat-sealed with a polyacid lactic (PLA) film. Preservation studies were carried out over 14 days of storage at refrigeration temperature (4 C). Raspberry samples were periodically analyzed throughout storage, in terms of quality attributes (fungal decay, weight loss, firmness, surface color, pH, total soluble solids), total phenolic content and antioxidant activity. Gas composition inside the packages was also analyzed over time. From the packaging systems tested, the ones with active film-pads Ch + GTE and Ch + RSME were highly effective in reducing fungal growth and decay of raspberry during storage, showing only around 13% and 5% of spoiled fruits after 14 days, respectively, in contrast with the packages without pads (around 80% of spoiled fruits detected). In addition, fruits preserved using packages with Ch + RSME active film-pads showed lower mass loss (5.6%), decreased firmness (3.7%) and reduced antioxidant activity (around 9% and 15% for DPPH and FRAP methods, respectively). This sustainable packaging presents a potential strategy for the preservation of raspberries and other highly perishable small fruitsinfo:eu-repo/semantics/publishedVersio

Design of chitosan and alginate emulsion-based formulations for the production of monolayer crosslinked edible films and coatings

This study aimed to develop edible monolayer emulsion-based barriers with polysaccharides as film-forming components (chitosan and sodium alginate), soy lecithin as a surfactant and olive oil as a hydrophobic barrier. Monolayer barriers in the form of films were prepared by casting filmogenic emulsions composed of 2% w/v chitosan (dissolved in lactic acid 1% v/v) or 1% w/v sodium alginate, with different lipid contents (25, 50 and 100% w/w biopolymer basis) and different surfactant concentrations (5, 10 and 25% w/w, lipid basis). Glycerol was used as a plasticizer (25 % w/w, biopolymer basis). After the emulsion drying process, the obtained stand-alone films were sprayed with a crosslinking solution, achieving an optimized crosslinker content of 3.2 mgCa2+/cm2 alginate film and 4 mg tripolyphosphate/cm2 chitosan film. The effect of oil and lecithin contents, as well the presence of crosslinking agents, on the film’s water vapour permeability (WVP), water vapour sorption capacity, mechanical properties and colour parameters, was evaluated. The results have shown that the lowest WVP values were obtained with formulations containing 25% lipid and 25% surfactant for chitosan films, and 100% lipid and 25% surfactant for alginate films. The application of the crosslinking agents decreased even further the WVP, especially for chitosan films (by 30%). Crosslinking also increased films’ resistance to deformation under tensile tests. Overall, the films developed present a good potential as polysaccharide-based barriers with increased resistance to water, which envisages the use of the designed formulations to produce either edible/biodegradable films or edible coatingsinfo:eu-repo/semantics/publishedVersio

Composite coatings of chitosan and alginate emulsions with olive oil to enhance postharvest quality and shelf life of fresh figs (Ficus carica L. cv. Pingo De Mel)

Fresh figs are very appreciated and have been associated with health benefits. However, these fruits are highly perishable. In this study, edible coatings were studied envisaging their positive effect in enhancing figs’ shelf-life. Fig fruits cv. ‘Pingo de mel’ were harvested at commercial ripening stage and single emulsion-based coatings, composed of chitosan + olive oil and alginate + olive oil, were applied. After coatings application by dipping each fruit in the emulsion-based solutions at 4 C and drying, the coated fruits were sprayed with crosslinking solutions (6% tripolyphosphate and 1% calcium chloride for chitosan and alginate-based coatings, respectively). Then, were maintained at 4 C and analyzed after 1, 7, 14 and 19 days of storage. After each time interval, fruits were further maintained at 25 C for 2 days. The results have shown that coatings were effective on delaying fungal decay and postharvest ripening indicators (respiration rate, mass loss, softening and total soluble solids/titratable acidity ratio). The results foresee a fruits’ shelf life between 14 and 19 days under refrigeration at 4 C that may be followed up to 2 days at ambient temperature, higher than that estimated for uncoated fruits (less than 14 days at 4 C plus to 2 days at ambient temperature)info:eu-repo/semantics/publishedVersio

Influence of a heat-shock pre-treatment on wound-induced phenolic biosynthesis as an alternative strategy towards fresh-cut carrot processing

In fresh-cut vegetables, plant tissues are often challenged by (a)biotic stresses that act in combination, and the response to combinatorial stresses differs from that triggered by each individually. Phenolic induction by wounding is a known response contributing to increase products phenolic content. Heat application is a promising treatment in minimal processing, and its interference on the wound-induced response is produce-dependent. In carrot, two-combined stress effects were evaluated: peel removal vs. shredding, and heat application (100 C/45 s) vs. shredding, on changes in total phenolic content (TPC) during 10 days (5 C). By applying the first stress combination, a decrease in TPC was verified on day 0 ( 50%), ascribed to the high phenolic content of peels. Recovery of initial fresh carrot levels was achieved after 7 days owing to phenolic biosynthesis induced by shredding. For the second combination, changes in TPC, phenylalanine-ammonia-lyase (PAL), and peroxidase (POD) activity of untreated (Ctr) and heat-treated (HS) peeled shredded carrot samples were evaluated during 10 days. The heat-shock did not suppress phenolic biosynthesis promoted by PAL, although there was a two-day delay in TPC increments. Notwithstanding, phenolic accumulation after 10 days exceeded raw material TPC content. Also, the decrease in POD activity (30%) could influence quality degradation during storageinfo:eu-repo/semantics/publishedVersio

Microencapsulation of beta-carotene by spray drying effect of wall material concentration and drying inlet temperature

Research ArticleCarotenoids are a class of natural pigments found mainly in fruits and vegetables. Among them, -carotene is regarded the most potent precursor of vitamin A. However, it is susceptible to oxidation upon exposure to oxygen, light, and heat, which can result in loss of colour, antioxidant activity, and vitamin activity.Thus, the objective of thiswork was to study themicroencapsulation process of -carotene by spray drying, using arabic gum as wall material, to protect it against adverse environmental conditions. This was carried out using the response surfacemethodology coupled to a central composite rotatable design, evaluating simultaneously the effect of drying air inlet temperature (110-200∘C) and the wall material concentration (5-35%) on the drying yield, encapsulation efficiency, loading capacity, and antioxidant activity. In addition, morphology and particles size distribution were evaluated. Scanning electron microscopy images have shown that the particles were microcapsules with a smooth surface when produced at the higher drying temperatures tested,most of them having a diameter lower than 10 m.The conditions that enabled obtaining simultaneously arabic gummicroparticles with higher -carotene content, higher encapsulation efficiency, and higher drying yield were a wall material concentration of 11.9% and a drying inlet temperature of 173∘C.The systematic approach used for the study of -carotene microencapsulation process by spray drying using arabic gum may be easily applied for other core and wall materialsinfo:eu-repo/semantics/publishedVersio

Food security and nutrition in Mozambique: comparative study with bean species commercialised in informal markets

In Mozambique (South-eastern Africa), Phaseolus vulgaris and Vigna spp. are important staple foods and a major source of dietary protein for local populations, particularly for people living in rural areas who lack the financial capacity to include meat in their daily dietary options. This study focuses on the potential for improving diets with locally produced nutritious legumes whilst increasing food security and income generation among smallholder farmers. Using bean species and varieties commercialised as dry legumes in the country, it sets out to characterize and compare the chemical properties of Phaseolus vulgaris and Vigna spp. among the most commercialised dry legume groups in Mozambique. The principal component analysis showed a clear separation between Phaseolus and Vigna species in terms of proximate composition, whereas protein content was quite uniform in both groups. It concludes that the introduction of improved cultivars of Phaseolus vulgaris and Vigna species maize–legume intercropping benefits yield, diets and increases household income with limited and low-cost inputs while enhancing the resilience of smallholder farmers in vulnerable production systems affected by recurrent drought and the supply of legumes to urban informal marketsinfo:eu-repo/semantics/publishedVersio

Exploring physicochemical and cytogenomic diversity of African cowpea and common bean

In sub-Saharan Africa, grain legumes (pulses) are essential food sources and play an important role in sustainable agriculture. Among the major pulse crops, the native cowpea (Vigna unguiculata) and introduced common bean (Phaseolus vulgaris) stand out. This paper has two main goals. First, we provide a comprehensive view of the available genetic resources of these genera in Africa, including data on germplasm collections and mapping biodiversity-rich areas. Second, we investigate patterns of physicochemical and cytogenomic variation across Africa to explore the geographical structuring of variation between native and introduced beans. Our results revealed that 73 Vigna and 5 Phaseolus species occur in tropical regions of Africa, with 8 countries accounting for more than 20 native species. Conversely, germplasm collections are poorly represented when compared to the worldwide collections. Regarding the nuclear DNA content, on average, V. unguiculata presents significantly higher values than P. vulgaris. Also, V. unguiculata is enriched in B, Mg, S, and Zn, while P. vulgaris has more Fe, Ca, and Cu. Overall, our study suggests that the physicochemical and cytogenomic diversity of native Vigna species is higher than previously thought, representing valuable food resources to reduce food insecurity and hunger, particularly of people living in African developing countriesinfo:eu-repo/semantics/publishedVersio