Assessment of the Bioactive Compounds, Color, and Mechanical Properties of Apricots as Affected by Drying Treatment

Consumer acceptance of dried apricots depends on them having an intense orange color, a gummy texture, and a characteristic flavor. In addition, the growing demand for healthy and nutritive foods has increased the interest in this product, as apricot fruits can be considered a good source of phytochemicals, such as polyphenols, carotenoids, and vitamins. Microwave energy may be an interesting drying method, an alternative to conventional sun or hot air drying, with which to obtain dried apricots with good sensorial, nutritive, and functional properties in a shorter time. This paper aims to evaluate the effect of sulfur pretreatment and the drying process (hot air and/or microwaves) on the color, mechanical properties, and ascorbic acid, vitamins A and E, and total carotenoid content of apricot. The obtained results mean that the use of microwave energy, either in combination or not with mild–hot air, may be recommended to obtain dried apricots, without needing to apply sulfur pretreatment.     

Effects of a citrus based juice on biomarkers of oxidative stress in metabolic syndrome patients

Bioactive substances found in numerous foods can be successfully and safely used to modify various cellular functions and affect the oxidative stress. The aim of this study was to analyze the effect of a citrus-based juice (juice citrus (95%) with 5% of aronia extract (Aronia melanocarpa)) on biomarkers of oxidative stress in patients with metabolic syndrome compared with healthy individuals. The study comprised 20 healthy subjects and 33 patients with metabolic syndrome. Eighteen patients consumed daily 300 mL of a citrus-based juice during 6 months and 15 patients consumed 300 mL of a placebo beverage. The control group consumed a citrus-based juice (CJ). Before, and at sixth months after consuming of a citrus-based juice the following parameters were determined: 15-isoprostane F₂, 8-hydroxydeoxyguanosine (8-OHdG), reduced and oxidized glutathione (GSH/GSSH), carbonyl groups and oxidized LDL (ox-LDL). After consuming CJ during 6 months the values of 8-OHdG, carbonyl groups and LDL-ox decreased in both analyzed groups and the values of GSH/GSSH increased. Significant differences were observed in both groups. Thus consumption of citrus-based juice improved the biomarkers of oxidative stress in metabolic syndrome patients.     

Dispersive Liquid–Liquid Microextraction Followed by Capillary High-Performance Liquid Chromatography for the Determination of Six Sulfonylurea Herbicides in Fruit Juices

In this study a simple, rapid, and efficient method has been developed for the determination of six sulfonylurea herbicides (SUHs): triasulfuron, metsulfuron-methyl, chlorsulfuron, flazasulfuron, chlorimuron-ethyl, and primisulfuron-methyl in commercial grape and apple juice samples, using dispersive liquid–liquid microextraction coupled with capillary high-performance liquid chromatography with diode array detection. Various parameters that influence the extraction efficiency, such as the type and volume of extraction and disperser solvents, sample pH, and salt addition, were investigated and optimized. Under the optimum conditions, limits of detection and quantification of the method were in the ranges of 2–9 and 8–29 μg L^?1, respectively, lower than the maximum residue limits set by the European Union for the raw fruits, such as grape and apple. The intra- and inter-day relative standard deviations varied from 1.0 to 8.2 and 1.8 to 9.8 %, respectively, with recoveries between 72.0 and 109.5 % for commercial grape (both white and red) and apple juice samples, showing satisfactory accuracy for the determination of SUHs in fruit juices.     

UHPLC as a suitable methodology for the analysis of carotenoids in food matrix

The purpose of this paper was to optimize an ultra-high performance liquid chromatography (UHPLC) method for the determination and quantification of carotenoid pigments in food products and compare it with a HPLC method in terms of resolution, selectivity, sensitivity, time and reagent saving. Less analysis times, solvent consumption and better peak resolution were achieved when the UHPLC methodology was used. Ultra-high performance liquid chromatography analysis was performed on Zorbax Eclipse Plus C18 column (2.1?×?50?mm; 1.8?μm) using a gradient solvent system and diode array detector. A total of seven carotenoids were separated and quantified in <8.5?min. For all components, the resolution was higher than 1.5 and LOD was below 1.0?μg?mL^?1. To determine the intraday and reproducibility, assays were conducted in 10 continuous days for method validation achieving recuperation rates ranging between 85 and 100?% and no significant differences among the results obtained in same and different days. The proposed methodology was applied for the determination of the carotenoid contents in honeybee pollen samples, pumpkin and nectarine flesh with satisfactory recovery.     

Edible and non-edible olive oils discrimination by the application of a sensory olfactory system based on tin dioxide sensors

An array of semiconductor sensors has been developed to discriminate virgin olive oil samples based on their organoleptic characteristics. The multisensor, developed at laboratory, is composed by 14 sensing elements of tin dioxide thin layers (doped with Cr and In, and undoped) deposited by the reactive sputtering technique. The sensors are stable and show good repeatability. Off-flavors and extra-virgin olive oil samples, taken at the outlet of the vertical centrifuge of a small experimental olive oil mill and sensory evaluated, have been used. A good discrimination of edible (extra-virgin and virgin) from non-edible (lampante) olive oils has been obtained through the statistical method of principal component analysis (PCA).     

Ochratoxigenic moulds and effectiveness of grape field antifungals in a climatic change scenario

BACKGROUND: The presence of ochratoxin A (OTA) in grapes and grape derivatives has been reported mainly in the Mediterranean area. Consequently, great efforts are being made to prevent the growth of Aspergillus on grapes. However, the European Commission suggests that climate change may result in increased temperatures and longer drought periods in southern Europe. Therefore the aim of this study was to investigate how ochratoxigenic fungal growth and the efficiency of fungicides used at present might be affected by environmental conditions predicted with climate change. RESULTS: The effectiveness of grape field antifungals (Switch, Flint Max and Equisetum arvense extract) under two alternating temperature, photoperiod and relative humidity (RH) scenarios (current: 20/30 °C, 16 h light/8 h darkness, 80% RH; predicted: 25/37 °C, 16 h light/8 h darkness, 75% RH) on the growth and OTA production of two Aspergillus carbonarius isolates and one Aspergillus ochraceus isolate on grapes was investigated. CONCLUSION: Predicted conditions reduced A. carbonarius and limited A. ochraceus growth. Antifungals reduced fungal infection (by 40‐84%), although no correlation between climatic conditions and effectiveness of the antifungals was found. However, Switch always showed the greatest reduction and E. arvense (0.02 g mL^?1 extract) the least. Higher temperatures affected OTA production by the isolates in different ways. In general, Switch and Flint Max reduced OTA production, while E. arvense stimulated it. Copyright © 2011 Society of Chemical Industry     

Effect of drying methods on the reactivity of chitosan towards Maillard reaction

The effect of drying methods on chitosan reactivity towards Maillard reaction during storage of dried chitosan–lactose systems was investigated. Two different structural forms of chitosan, scaffold and microspheres, were prepared. Then they were dried by lyophilization or using supercritical fluid technology (SF-CO₂) and stored with lactose under controlled temperature conditions (60 °C) and water activity (a_w = 0.65). The drying method produced slight modifications on the chitosan structure especially in samples submitted to SF-CO₂ treatment. Differences were more evident in the reactivity of chitosan–lactose systems during storage. Maillard reaction development was assessed by quantification of a new compound which originated from the acid hydrolysis of Amadori compounds (NFMD) resulting from chitosan–lactose interactions, and not detected in the acid hydrolysates of freshly prepared chitosan-lactose systems. Maillard reaction was influenced by different factors such as the manner of lactose addition, structure of chitosan (microspheres and scaffolds) and drying method. Lyophilized chitosan in the form of microspheres with lactose, presented the highest values of NFMD (428.45 mg/100 g of sample). The determination of this compound could be used as an index of the progress of Maillard reaction.     

Quality enhancement of the abundant under‐valued crustacean,lobster krill (Munida spp.), during its chilled storage

Lobster krill (Munida genus) represents an under‐valued crustacean frequently caught on European fishing banks. In this work, its sensory, microbiological and biochemical qualities were evaluated during chilled storage. Additionally, the effects of a prestorage antimelanosic treatment consisting of soaking in sodium metabisulphite (SMB) solutions at two different concentrations (0.25% and 0.75%) were also studied. SMB prestorage treatment provided lobster specimens that still exhibited acceptable sensory quality after 10 days of storage, while control specimens were unacceptable at that time. SMB treatment also resulted in a significant (P < 0.05) inhibition of microbial growth, mainly of Enterobacteriaceae, psychrotrophes and proteolytic bacteria. Low lipid oxidation levels were observed for all batches; however, a significantly higher (P < 0.05) retention of polyunsaturated fatty acids was found in SMB‐treated lobster, especially in the 0.75% SMB batch. The results presented here open the way to the potential commercialisation of currently under‐utilised lobster krill as a chilled product.