Qualitative, Metabolic and Nutritional Aspects of Traditional and Innovative Minimally Processed Fruit

Minimally processed fruit (MPF) are products that have to maintain their quality similar to those of fresh ones. Being metabolic active tissues, they show physical and physiological response to minimal processing (wounding), that negatively influence their shelf-life. In the last decades, novel non-thermal processing methods have attracted the interest of food scientists, industries and consumers as technologies useful for shelf-life extension or increasing product functionality, with a minimal impact on the nutritional and sensory properties of foods. The main aim of this PhD thesis was to investigate qualitative, metabolic and nutritional aspects of different MPF, submitted to traditional and innovative non-thermal processes. This issue was addressed considering the product as a dynamic system, both in terms of endogenous physiological activity and porous matrix interacting with the surrounding ambient (during processing and storage), through the application of multi-analytical approach. The most consistent results related to the applied non-thermal techniques confirmed their different potentiality in the optic of processing and product innovation, but the need of their modulation in relation to the different raw material susceptibility to degradation and final product target. Cold plasma treatment effects on fresh-cut fruit, characterized by different kind of stability criticisms, resulted mainly bound to the inactivation of degradative enzymes and microbial cells, without evidencing functional modifications in the final products. The study of osmotic dehydration and vacuum impregnation highlighted as these techniques can be successfully applied for cold formulation/enrichment of MPF, but also the necessity to carefully account for the metabolic and structural modifications induced by the processing on the vegetable tissues. An induction of metabolic stress response was also evidenced as a consequence of pulsed electric fields treatment related to electric field strength. Below the threshold limit of irreversible damages to cell membranes, the treatment promoted only slight and reversible modifications of the metabolic profiles

Safety, Quality and Processing of Fruits and Vegetables

Nowadays, one of the main objectives of the fruit and vegetable industry is to develop innovative novel products with high quality, safety, and optimal nutritional characteristics in order to respond, with efficiency, to increasing consumer expectations. Various unconventional technologies (e.g., pulsed electric field, pulsed light, ultrasound, high pressure, and microwave drying) have emerged and enable the processing of fruits and vegetables in a way that increases their stability while preserving their thermolabile nutrients, flavour, texture, and overall quality. Some of these technologies can also be used for waste and byproduct valorisation. The application of fast noninvasive methods for process control is of great importance for the fruit and vegetable industry. The following Special Issue “Safety, Quality, and Processing of Fruits and Vegetables” consists of 11 papers which represent a high-value contribution to the existing knowledge on safety aspects, quality evaluation, and emerging processing technologies for fruits and vegetables

Influence of lupin and chickpea flours on acrylamide formation and quality characteristics of biscuits

Asparagine and sugars are direct precursors of acrylamide; however, proteins and fibres can also influence it. In this study, biscuits prepared replacing wheat flour with increasing concentrations (20, 40, 60%) of lupin or chickpea flour were investigated. Asparagine concentration was equalized in all formulas to isolate the effect of other flour characteristics on the acrylamide formation during baking. The results showed that replacing wheat flour with lupin flour increased acrylamide from 583.9 up to 1443 µg/kg after 9 min of baking, while 20-40% chickpea flour reduced acrylamide to 354.4-312.6 µg/kg. The acrylamide reduction using chickpea was attributed to the lower interaction between precursors resulting from both the coarser particle size and the lower reactivity of carbohydrate in presence of chickpea proteins. Chickpea addition did not affect the colour and texture of biscuits, opening the possibility for large-scale implementation of this mitigation strategy in formulas with a similar initial asparagine content

Ultrasound assisted osmotic dehydration of organic cranberries (Vaccinium oxycoccus): Study on quality parameters evolution during storage.

Cranberries are appreciated for their high amount of antioxidants such as flavonoids, anthocyanins,phenolic acids, carotenoids and vitamins. However, due to their sour and tart taste they request to beprocessed into sweeter dried fruits in order to be acceptable for the consumers. The aim of this work wasto analyse the effect of ultrasound assisted osmotic dehydration on mass transfer parameters and onquality characteristics during storage of cranberries. Ultrasound treatment was performed at the fre-quency of 21 kHz for 30 min in three osmotic solutions - 61.5% sucrose, 30% sucrose with an addition of0.1% of steviol glycosides and 40% trehalose on cut in half cranberries. Afterwards, the cranberry sampleswere subjected to osmotic dehydration process at 40C for 72 h. The osmodehydrated samples both withor without ultrasound pre-treatment were collected and stored at 10C in climatic chamber in micro-perforated plastic bags (PLA) for 8 weeks. The weight reduction, dry matter, water activity, colour, andmicrobiological analysis were performed after 1, 2, 4 and 8 weeks of storage. The obtained resultsindicated that ultrasound application significantly affected the mass transfer parameters during osmotictreatment, as well as it did the type of osmotic solution used. Thermal analysis showed variations insugar melting temperature and enthalpy as a result of osmotic treatment and storage. During the storage,lower weight loss and higher lightness were observed in US pre-treated samples. The sample thatpreserved the best chemico-physical and microbiological characteristics during storage was the onetreated with 61.5% sucrose solution, due to its lowest water activity

Assessment of lipid oxidation and microbial decontamination of sardine (Sardina pilchardus) fillets processed by plasma-activated water (PAW)

Plasma activated water (PAW) is emerging as a mild and environmentally friendly technology for microbial and chemical decontamination of food. The aim of this work was to evaluate the degree of oxidation of lipids of sardine tissue treated by PAW generated with a pulsed corona discharge. The effect of PAW on the natural microflora of the fish was also evaluated. Under the adopted experimental conditions, PAW was able to reduce the number of mesophilic aerobes and Pseudomonas spp. by 0.22 and 0.20 log units, respectively, but no increase in shelf life was observed at chilling temperatures compared to water washing. A loss of polyunsaturated fatty acids (PUFAs) and an increase in volatile oxidation products derived from the cleavage of PUFA hydroperoxides were observed at the longest treatment duration. Twelve cholesterol oxidation products (COPs) were identified in sardine lipids, but no significant differences in total COPs content were observed between PAW processed and control samples. Free radical mediated oxidation pathways led to the most abundant COPs, but a significant contribution of non-radical pathways was also observed. Further studies are needed to better understand the low efficiency of PAW in microbial decontamination of proteinaceous materials

Quality Changes during Frozen Storage of Mechanical-Separated Flesh Obtained from an Underutilized Crustacean

Despite their high nutritional value, high quantities of fish caught in the Adriatic Sea are underused or discarded for their insignificant economic value. Mechanical separation of flesh represents an opportunity for developing innovative semi-finished products, even if it can promote an increased quality degradation rate. The aim of this study was to evaluate physico-chemical modifications of mechanically separated mantis shrimp flesh during deep-freezing storage. Flesh samples obtained using a belt-drum separator, frozen and vacuum-packed, were stored at 3 temperatures (industrial: -26 \ub0C; domestic: -18 \ub0C and abuse: -10 \ub0C) for 12 months. During storage, qualitative (color, water content, pH, fatty acids (FA) and lipid oxidation) were evaluated. Fish freshness parameters (e.g., trimethylamine (TMA), dimethylamine (DMA) and amino acids) were assessed using nuclear magnetic resonance (1H-NMR). The mechanical separation process accelerated the initial oxidation phenomena, promoting color alterations, compared to manual separation. The main degradation phenomena during storage were significantly affected by temperature and were related to changes in luminosity, oxidation of n-3 polyunsaturated fatty acids (PUFA), increased lipolysis with release of free FA, production of TMA and DMA by residual enzymatic activity, and changes in amino acids due to proteolysis. The inter-disciplinary approach permitted important findings to be made, in terms of the extent of different degradative phenomena, bound to processing and storage conditions of mechanically separated mantis flesh

Effect of cold plasma generated with different gas mixtures on safety, quality and nutritional aspects of fresh sea bream fillets

Cold atmospheric plasma (CAP) is a non-thermal technology, successfully used to decontaminate and extend the shelf-life of various foods. However, since CAP is highly oxidative, it can cause quality deterioration in sensitive matrices, such as fish products. This research aimed to evaluate the effect of CAP treatment with a surface dielectric barrier discharge (SDBD) with different gas mixtures (80% Ar/20% O2, or 80% N2/20% O2) on the decontamination of inoculated pathogens (E.coli and L.innocua; log 4 CFU/g inoculum) and endogenous spoilage microbiota and on the main quality indices of seabream (Spaurus aurata) fillets. For selected appropriate treatments, the impact on the nutritional value of the products was investigated through in vitro digestion, bioaccessibility of fatty acids and the degree of protein hydrolysis. The use of CAP resulted in a decrease in the bacterial load in the fresh sea bream fillets up to 1 log CFU/g obtained with Ar/O2 gas mixture for 20 min, affected by the treatment duration, but not by the gas mixture. Although a slight increase in lipid oxidation was observed (from 0.5 mg MDA/kg to a maximum of 4 mg MDA/kg), the digestibility of the products was not affected. Industrial relevance From an industrial point of view, increasing shelf-life of perishable products such as fish fillets with an environmentally friendly and non-thermal technology could represent a great advantage; however, maintaining quality is of paramount importance for the industrial use of this novel processing technology. The results of the present study show negligible effects on the nutritional quality of seabream fillets, which encourages further research.publishedVersio

Potential of Natural Antimicrobials for the Production of Minimally Processed Fresh-Cut Apples

Background: Minimally processed fruit are susceptible to microbial spoilage and loss of sensory quality. In this experimental work, in order to increase the shelf-life and to maintain quality parameter (texture and colour) of sliced apples (Malus communis, var. Golden delicious), the use of natural antimicrobials was proposed. Materials and methods: Natural antimicrobials were purposed to produce fresh-cut apples. Hexanal, citral, and combinations of hexanal+citral, citron essential oil+carvacrol, citral+2-(E)-hexenal, citral+citron essential oil and hexanal+2- (E)-hexenal were used in dipping step. After treatment, sample were stored at 6°C in ordinary atmosphere. During storage, yeast and lactic acid bacteria were monitored. Also volatile and electronic nose profiles, colour and texture analyses were considered. The samples were compared with a control (apples dipped in ascorbic and citric acid solution). Results: Yeast cell loads showed that natural antimicrobials changed naturally occurring yeast growth parameters. The combination of citron+carvacrol prolonged the yeast lag phase of 6 d comparing with control, while citral and hexanal+2-(E)- hexenal decreased the maximum reached yeast cell load and growth rate, respectively. After 8 d, samples with hexanal+2-(E)- hexenal and citral showed equivalent or even better quality attributes compared to the controls, suggesting that this approach is a useful tool for fresh-cut apple production. Highlight: Natural antimicrobial can be useful for the dipping of minimally processed apples Citral and hexanal+2-(E)-hexenal prolonged the apples shelf-life. Apples treated with Citral and hexanal+2-(E)-hexenal had good quality attributes

Multicentre Italian study of SARS-CoV-2 infection in children and adolescents, preliminary data as at 10 April 2020

Data on features of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in children and adolescents are scarce. We report preliminary results of an Italian multicentre study comprising 168 laboratory-confirmed paediatric cases (median: 2.3 years, range: 1 day-17.7 years, 55.9% males), of which 67.9% were hospitalised and 19.6% had comorbidities. Fever was the most common symptom, gastrointestinal manifestations were frequent; two children required intensive care, five had seizures, 49 received experimental treatments and all recovered

Quality Changes during Frozen Storage of Mechanical-Separated Flesh Obtained from an Underutilized Crustacean

Despite their high nutritional value, high quantities of fish caught in the Adriatic Sea are underused or discarded for their insignificant economic value. Mechanical separation of flesh represents an opportunity for developing innovative semi-finished products, even if it can promote an increased quality degradation rate. The aim of this study was to evaluate physico-chemical modifications of mechanically separated mantis shrimp flesh during deep-freezing storage. Flesh samples obtained using a belt-drum separator, frozen and vacuum-packed, were stored at 3 temperatures (industrial: −26 °C; domestic: −18 °C and abuse: −10 °C) for 12 months. During storage, qualitative (color, water content, pH, fatty acids (FA) and lipid oxidation) were evaluated. Fish freshness parameters (e.g., trimethylamine (TMA), dimethylamine (DMA) and amino acids) were assessed using nuclear magnetic resonance (1H-NMR). The mechanical separation process accelerated the initial oxidation phenomena, promoting color alterations, compared to manual separation. The main degradation phenomena during storage were significantly affected by temperature and were related to changes in luminosity, oxidation of n-3 polyunsaturated fatty acids (PUFA), increased lipolysis with release of free FA, production of TMA and DMA by residual enzymatic activity, and changes in amino acids due to proteolysis. The inter-disciplinary approach permitted important findings to be made, in terms of the extent of different degradative phenomena, bound to processing and storage conditions of mechanically separated mantis flesh