Diagnostics of plasma reactive species and induced chemistry of plasma treated foods.

Cold plasma is a promising technique that has been tested as a process technology for a range of food commodities, mainly to destroy microorganisms, but also aimed at toxin degradation, enzyme inactivation, residual pesticide degradation and functionalization of food properties. Plasma has already been employed by industry for food packaging material sterilization and surface modification. As most of the current literature on cold plasma in the field of food science is focused on microbial inactivation efficacy, the information about its chemical influences on food is sparse. To better understand the chemical interactions of with plasma, this review focuses on plasma chemistry diagnostics techniques available to characterize the plasma reactive species generated. Equally important is the detection of induced chemistry in the food and here we present approaches to analyze likely reactions with key food bio-molecules. Such analysis will support mechanistic insights involved in these complex chemical reactions (i.e., DNA, lipid and protein) along with potential physical modifications of the food structure. For successful adoption of plasma as a food processing aid it is critical to elucidate these interactions as they have an important role in demonstrating the technology's safety as a food processing technique along with understanding any effect on food nutrients.

Enhancement of phytochemical content and drying efficiency of onions (Allium cepa L.) through blanching.

BACKGROUND: This study investigated the effect of blanching (60, 70 and 80 °C for 1, 3, 5 and 10 min) combined with oven drying at 60 °C on the phenolic compounds, antioxidant activity, colour and drying characteristics (drying time, drying rate constant, effective moisture diffusivity and activation energy) of onion slices. RESULTS: Blanching of onion slices at 60 °C for 3 min and at 70 °C for 1 min prior to drying increased their bioactive compounds and antioxidant activity compared to the control samples and other treatments. Eighteen drying models were evaluated. The Modified Page and two-term exponential models best represented the drying data. The effective diffusivity ranged from 3.32 × 10-11 m2 s-1 (control) to 5.27 × 10-11 m2 s-1 , 5.01 × 10-11 m2 s-1 , and 4.74 × 10-11 m2 s-1 for onions blanched at 60 °C, 70 °C and 80 °C, respectively. The higher activation energy was observed for the control (unblanched) sample and slightly lower values were found for 1 min- and 3 min-blanched samples, confirming the higher drying efficiency as a result of the blanching pre-treatment. CONCLUSION: The use of blanching as a pre-treatment before drying of onions resulted in enhanced phytochemical content and drying efficiency. © 2017 Society of Chemical Industry.

Valorization of Apple Pomace by Extraction of Valuable Compounds.

Apple pomace is a promising source of carbohydrates, proteins, amino acids, fatty acids, phenolic compounds, vitamins, and other compounds with a vast range of food applications. This review focuses on the valorization of apple pomace towards the recovery of the main compounds, namely pectin and polyphenols. Applications, advantages, and drawbacks of conventional extraction (acidic medium under high temperatures) compared with novel extraction technologies are presented. The comparison is based on an extensive literature review of research on extraction of valuable compounds from plant matrixes, particularly apple pomace. Novel extraction techniques involving enzymes, electric field, ultrasound, microwave heating, pressurized liquid, and super/subcritical fluid are also discussed. These techniques offer several advantages, including shorter extraction time, increased yield, reduction-or suppression-of solvents, and minimization of the environmental impact. This paper may help researchers and food industry professionals on the scaling-up and optimization of eco-friendly extractions of pectin and phenolic compounds.

Effect of storage, food processing and novel extraction technologies on onions flavonoid content: A review.

Onions play an important part in the daily diet for most populations around the world owing to their nutritional composition and their unique capacity to naturally flavor dishes. Onions contain quercetin and its derivatives - the predominant flavonoid in onions that exert a great contribution to the effective bioactive properties of onion, including its derived products. The present paper comprehensively reviewed flavonoids (with a specific focus on quercetin in onions): their chemical composition, distribution, bioactivities in onion, and impacting factors with a focus on how they can be affected by various post-harvest conditions (storage and food processing). In addition, research on the extraction of flavonoid compounds from onions using a number of novel technologies was also reviewed.

Ultrasonic-assisted incorporation of nano-encapsulated omega-3 fatty acids to enhance the fatty acid profile of pork meat.

In this study, ultrasound was employed to enhance the diffusion of microencapsulated fatty acids into pork meat. Nanovesicles of fish oil composed of 42% EPA (eicosapentanoic acid) and 16% DHA (docosahexanoic acid) were prepared using two different commercial Pronanosome preparations (Lipo-N and Lipo-CAT; which yield cationic and non-cationic nanovesicles, respectively). The thin film hydration (TFH) methodology was employed for encapsulation. Pork meat (Musculus semitendinosus) was submerged in the nanovesicles suspension and subjected to ultrasound (US) treatment at 25kHz for either 30 or 60min. Samples were analysed for fatty acid composition using gas chromatography-flame ionisation (GC-FID). The content of long-chain PUFAs, especially omega-3, was found to increase following the US treatment which was higher for Lipo-CAT compared to Lipo-N nanovesicles. Samples subjected to Lipo-N had higher atherogenic and thrombogenic indices, indicating higher levels of saturated fatty acids compared to the Lipo-CAT. The omega-6/omega-3 ratio in pork meat was significantly reduced following the US treatment, thus indicating an improved fatty acid profile of pork.