Autochthonous Apple Cultivars from the Campania Region (Southern Italy): Bio-Agronomic and Qualitative Traits.

Apple (Malus × domestica Borkh.) is an important fruit crop widely spread in the cold and mild climates of temperate regions in the world, with more than 93 million tons harvested worldwide in 2021. The object of this work was to analyze thirty-one local apple cultivars of the Campania region (Southern Italy) using agronomic, morphological (UPOV descriptors) and physicochemical (solid soluble content, texture, pH and titratable acidity, skin color, Young's modulus and browning index) traits. UPOV descriptors highlighted similarities and differences among apple cultivars with a depth phenotypic characterization. Apple cultivars showed significant differences in fruit weight (31.3-236.02 g) and physicochemical trait ranging from 8.0 to 14.64° Brix for solid soluble content, 2.34-10.38 g malic acid L-1 for titratable acidity, and 15-40% for browning index. Furthermore, different percentages in apple shape and skin color have been detected. Similarities among the cultivars based on their bio-agronomic and qualitative traits have been evaluated by cluster analyses and principal component analyses. This apple germplasm collection represents an irreplaceable genetic resource with considerable morphological and pomological variabilities among several cultivars. Nowadays, some local cultivars, widespread only in restricted geographical areas, could be reintroduced in cultivation contribution to improving the diversity of our diets and contemporary to preserve knowledge on traditional agricultural systems.

Agronomic, Physicochemical, Aromatic and Sensory Characterization of Four Sweet Cherry Accessions of the Campania Region.

Sweet cherries (Prunus avium L.) are greatly appreciated fruits worldwide due to their taste, color, nutritional value, and beneficial health effects. The characterization of autochthonous germplasm allows to identify genotypes that possess superior characteristics compared to standard cultivars. In this work, four accessions of sweet cherry from the Campania region (Limoncella, Mulegnana Riccia, Mulegnana Nera and Montenero) were investigated for their morpho-physiological, qualitative, aromatic, and sensorial traits in comparison with two standard cultivars (Ferrovia and Lapins). A high variability in the pomological traits resulted among the samples. Montenero showed comparable fruit weight and titratable acidity to Ferrovia and Lapins, respectively. The highest total soluble solid content was detected in Mulegnana Riccia. A considerable variability in the skin and pulp color of the cherries was observed, varying from yellow-red in Limoncella to a dark red color in Montenero. Mulegnana Nera showed the highest content of polyphenols, flavonoids, anthocyanins, and ascorbic acid compared to the standard cultivars. Volatile organic compounds profile analysis identified 34 volatile compounds, 12 of which were observed at different concentrations in all the sweet cherry genotypes while the others were genotype-dependent. Conservation and cultivation of autochthonous accessions with suitable nutritional and morpho-physiologic characteristics promotes our agrobiodiversity knowledge and allows to better plan future breeding programs.

Response of Qualitative Traits and Antioxidant Systems to Chitosan Postharvest Treatment in 'Black Golden' Japanese Plum.

In this study, the influence of a chitosan-based coating was assessed on qualitative traits and non-enzymatic and enzymatic antioxidant systems in Prunus salicina, 'Black Golden' Japanese Plum, during 35 days of cold storage followed by 3 days at 24 °C to evaluate its shelf life. Chitosan coating delayed the physico-chemical traits such as the total soluble solids, titratable acidity, firmness and skin color associated with the plum ripening process during cold storage and shelf life. Furthermore, the highest bioactive compounds' content and antioxidant activity in the coated plum were registered during the stored period. Chitosan-based coating enhanced the activities of superoxide dismutase and ascorbate peroxidase during cold storage and shelf-life. Moreover, this edible coating contributes to reducing membrane damages with lower lipoxygenase activity and, consequently, malondialdehyde accumulation. A multivariate statistical analysis approach identified the two key components, correlated to all analyzed traits, that influenced the changes within chitosan coated and uncoated Japanese plums during storage. Chitosan coating is a cheap and eco-friendly tool to delay ripening process and to improve the antioxidant systems and storability of the 'Black Golden' Japanese plum.

Microwave and Ultrasound Pre-Treatments for Drying of the "Rocha" Pear: Impact on Phytochemical Parameters, Color Changes and Drying Kinetics.

The objective of this research was to evaluate the effect of drying temperature and innovative pre-treatments (i.e., microwave and ultrasound) on "Rocha" pear drying behavior and quality characteristics, such as color, total phenolic content and antioxidant activity. Experiments were carried out with pear slabs subjected to microwaves (2450 MHz, 539 W, 4 min, microwave oven) and ultrasounds (35 kHz, 10 min, in an ultrasonic bath) as well as control samples. The drying process was conducted in a tray dryer at three different temperatures (50, 55 and 60 °C) and a fixed air velocity of 0.75 m/s. Microwave technology resulted in a higher quality deterioration in dried pear samples compared to those of controls and ultrasound pre-treated samples. The combined application of ultrasound pre-treatment and the higher drying temperature of 60 °C was characterized by the lowest color changes (ΔE = 3.86 ± 0.23) and higher preservation of nutritional parameters (total phenolic content, TPC = 345.60 ± 8.99; and antioxidant activity, EC50 = 8.80 ± 0.34). The drying characteristics of pear fruits were also analyzed by taking into account empirical models, with the Page model presenting the best prediction of the drying behavior. In conclusion, ultrasound application is a promising technology to obtain healthy/nutritious dried "Rocha" pear snacks as dietary sources for consumers.

Multifunctional Role of Chitosan Edible Coatings on Antioxidant Systems in Fruit Crops: A Review.

Chitosan-based edible coatings represent an eco-friendly and biologically safe preservative tool to reduce qualitative decay of fresh and ready-to-eat fruits during post-harvest life due to their lack of toxicity, biodegradability, film-forming properties, and antimicrobial actions. Chitosan-based coatings modulate or control oxidative stress maintaining in different manner the appropriate balance of reactive oxygen species (ROS) in fruit cells, by the interplay of pathways and enzymes involved in ROS production and the scavenging mechanisms which essentially constitute the basic ROS cycle. This review is carried out with the aim to provide comprehensive and updated over-view of the state of the art related to the effects of chitosan-based edible coatings on anti-oxidant systems, enzymatic and non-enzymatic, evaluating the induced oxidative damages during storage in whole and ready-to-eat fruits. All these aspects are broadly reviewed in this review, with particular emphasis on the literature published during the last five years.

Evolution of Carotenoid Content, Antioxidant Activity and Volatiles Compounds in Dried Mango Fruits (Mangifera Indica L.).

The aim of this research was to study the evolution of carotenoid compounds, antioxidant ß-ctivity, volatiles and sensory quality in two mango cultivars dried at 50, 60 and 70 °C. Total carotenoids in fresh samples were about 12 and 6 mg/100 g (dry basis) in Keitt and Osteen samples, respectively. ß-carotene was the main carotenoid, representing about 50% of total carotenoids. In both cultivars, carotenoids were more susceptible to drying at 60 °C. Total phenols and metal reduction activity were higher in Osteen than in Keitt, which had higher values in radical scavenging capacity. The antioxidant activities were best preserved with drying temperatures at 50 °C in Keitt and 60 °C in Osteen fruits. Fresh Osteen mango fruits had a volatile compound content of about 37.1, while Keitt of about 5.2 mg/kg (dry basis). All the compounds with odorous impact were significantly reduced after drying. As regards organoleptic characteristics through sensory analysis, Keitt dried mangoes were quite similar to the fresh product, compared to Osteen.

Influence of Different Hot Air Drying Temperatures on Drying Kinetics, Shrinkage, and Colour of Persimmon Slices.

Drying characteristics of persimmon, cv. "Rojo Brillante", slabs were experimentally determined in a hot air convective drier at drying temperatures of 45, 50, 55, 60, and 65 °C at a fixed air velocity of 2.3 m/s. It was observed that the drying temperature affected the drying time, shrinkage, and colour. Four empirical mathematical models namely, Enderson and Pabis, Page, Logarithmic, and Two term, were evaluated in order to deeply understand the drying process (moisture ratio). The Page model described the best representation of the experimental drying data at all investigated temperatures (45, 50, 55, 60, 65 °C). According to the evaluation of the shrinkage models, the Quadratic model provided the best representation of the volumetric shrinkage of persimmons as a function of moisture content. Overall, higher drying temperature (65 °C) improved the colour retention of dried persimmon slabs.

Impact of dealcoholization on quality properties in white wine at various alcohol content levels.

The reduction of alcohol content in wines has two main objectives, the former is decreasing the wines' strength and the latter is producing new low alcohol beverages. To accomplish the latter, in this study, we focused on the dealcoholization of a white wine (cv Falanghina, 12.5 vol%) obtained from an ancient Italian grape variety that has recently aroused a renewed interest. It was dealcoholized at various alcohol content levels ranging from 9.8 to 0.3 vol% through the osmotic distillation process, and the main quality parameters of the obtained dealcoholized samples were evaluated. No significant differences (p < 0.05) in total phenols, flavonoids, organic acids and total acidity were observed among the wine samples at different alcohol content levels. On the contrary, the volatile compounds content decreased with increasing alcohol removal. Specifically, almost 50% of higher alcohols with acids and lactones were preserved in dealcoholized wine at 9.8 vol% alcohol content, but this percentage reduced to 30% in the sample at 6.8 vol%, and was even lower in the dealcoholized wine with lower alcohol content. It was argued that the transport of volatile compounds through the membrane, beside the membrane selectivity, is highly correlated with the Henry constant (R2 > 0.8021 for 9.8 vol% of dealcoholized wine). Moreover, results of the sensory evaluation indicated a significant change in terms of acidity, odour, sweetness and body taste in dealcoholized wine (0.3 vol%), giving an overall perceived imbalance and unacceptable taste with respect to the original wine. Therefore, in order to balance acid sensation and enhance body and aftertaste, an attempt was made to formulate an alcohol-free wine-based beverage with enhanced odour and sweetness, by adding some floral wine flavours, up to the amount present in the original wine.

Fabrication of SrTiO3 Layer on Pt Electrode for Label-Free Capacitive Biosensors.

Due to their interesting ferroelectric, conductive and dielectric properties, in recent years, perovskite-structured materials have begun to attract increasing interest in the biosensing field. In this study, a strontium titanate perovskite layer (SrTiO3) has been synthesized on a platinum electrode and exploited for the development of an impedimetric label-free immunosensor for Escherichia coli O157:H7 detection. The electrochemical characterization of the perovskite-modified electrode during the construction of the immunosensor, as well as after the interaction with different E. coli O157:H7 concentrations, showed a reproducible decrease of the total capacitance of the system that was used for the analytical characterization of the immunosensor. Under optimized conditions, the capacitive immunosensor showed a linear relationship from to 1 to 7 log cfu/mL with a low detection limit of 1 log cfu/mL. Moreover, the atomic force microscopy (AFM) technique underlined the increase in roughness of the SrTiO3-modified electrode surface after antibody immobilization, as well as the effective presence of cells with the typical size of E. coli.

A highly sensitive impedimetric label free immunosensor for Ochratoxin measurement in cocoa beans.

In this work the development and optimization of an impedimetric label free immunosensor for the detection of Ochratoxin A (OTA) is reported. Two antibody immobilization methods (oriented and not oriented) were compared highlighting a lower limit of detection (5pg/ml) for the not oriented immobilization but a closer linear range in contrast to oriented anti-OTA immunosensors which showed linearity in the range of 0.01-5ng/mL OTA. The analysis of the Atomic Force Microscopy (AFM) images showed two different nanostructures indicating that the use of oriented immobilization created a more ordered and highly dense antibody surface. Finally the oriented immunosensor was used to quantify OTA in spiked cocoa bean samples and the results were compared with those registered with competitive ELISA kit. The immunosensor was sensitive to OTA lower than 2µg/kg that represents the lower acceptable limit of OTA established by European legislation for the common food products.

A doped polyaniline modified electrode amperometric biosensor for gluconic acid determination in grapes.

In winemaking gluconic acid is an important marker for quantitative evaluation of grape infection by Botrytis cinerea. A screen-printed amperometric bienzymatic sensor for the determination of gluconic acid based on gluconate kinase (GK) and 6-phospho-D-gluconate dehydrogenase (6PGDH) coimmobilized onto polyaniline/poly (2-acrylamido-2-methyl-1-propanesulfonic acid; PANI-PAAMPSA) is reported in this study. The conductive polymer electrodeposed on the working electrode surface allowed the detection of NADH at low potential (0.1 V) with a linear range from 4 × 10(-3) to 1 mM (R2 = 0.99) and a sensitivity of 419.44 nA∙mM(-1). The bienzymatic sensor has been optimized with regard to GK/6PGDH enzymatic unit ratio and ATP/NADP+ molar ratio which resulted equal to 0.33 and 1.2, respectively. Under these conditions a sensitivity of 255.2 nA∙mM(-1), a limit of detection of 5 µM and a Relative Standard Deviation (RSD) of 4.2% (n = 5) have been observed. Finally, the biosensor has been applied for gluconic acid measurements in must grape samples and the matrix effect has been taken into consideration. The results have been compared with those obtained on the same samples with a commercial kit based on a spectrophotometric enzyme assay and were in good agreement, showing the capability of the bienzymatic PANI-PAAMPSA biosensor for gluconic acid measurements and thus for the evaluation of Botrytis cinerea infection in grapes.

Degradation of carotenoids in apricot (Prunus armeniaca L.) during drying process.

Carotenoids are natural compounds whose nutritional importance comes from the provitamin A activity of some of them and their protection against several serious human disorders. The degradation of carotenoids was investigated during apricot drying by microwave and convective hot-air at 60 and 70 °C. Seven carotenoids were identified: antheraxanthin, lutein, zeaxanthin, ß-cryptoxanthin, 13-cis-ß-carotene, all-trans-ß-carotene and 9-cis-ß-carotene; among these, all-trans-ß-carotene was found to be about 50 % of total carotenoids. First-order kinetic models were found to better describe all-trans-ß-carotene reduction during drying, with a degradation rate constant (k1) that increased two folds when temperatures increased by 10 °C, in both methods. No differences were found in k1 between apricots dried by hot air at 70 °C (k1 = 0.0340 h(-1)) and by microwave at 60 °C. The evolution of total carotenoids (117.1 mg/kg on dry basis) during drying highlighted a wider decrease (about 50%) when microwave heating was employed, for both set temperatures. Antheraxantin was found to be the carotenoid most susceptible to heat, disappearing at 6 h during both trials with microwave as well as during convective hot-air at 70 °C. For this reason, antheraxanthin could be a useful marker for the evaluation of thermal damage due to the drying process. Also the degree of isomerization of all-trans-ß-carotene could be a useful marker for the evaluation of the drying process.

Evolution of quality parameters during red wine dealcoholization by osmotic distillation.

Osmotic distillation technique was used for the total dealcoholization of a red wine (Aglianico grape variety) up to 0.19 vol.%. The dealcoholization process was performed in subsequent cycles which gave rise wine samples at different alcoholic degrees. The effect of processing on the main chemical and physical properties of Aglianico wine was evaluated. Among wine samples, no significant differences (p<0.05) of oenological parameters such as pH, total acidity were found. Similarly, the total phenolic, flavonoids and tartaric esters content and the composition of organic acids did not show significant differences (p<0.05) during the process. On the contrary, colour intensity and tonality of wine samples changed significantly when the alcohol reduction was over the 6.5 vol.%. Finally, the total dealcoholized wine showed properties similar to Aglianico wine except for the volatile compounds, which decreased over 98%. Hence, flavour enrichment may be required to produce a pleasurable and delicious non alcoholic beverage from wine.