Olive oil production is characterized by large amounts of waste, and yet is considerably highly valued. Olive pomace can serve as a cheap source of bioactive compounds (BACs) with important antioxidant activity. Novel technologies like Pulsed Electric Fields (PEF) and High Pressure (HP) and microwave (MW) processing are considered green alternatives for the recovery of BACs.
View Article and Find Full Text PDFThis study focused on the osmotic dehydration (OD) of ready-to-eat spinach leaves combined with the pulsed electric field (PEF) pre-treatment. Untreated and PEF-treated (0.6 kV/cm, 0-200 pulses) spinach leaves were osmotically dehydrated at room temperature for up to 120 min.
View Article and Find Full Text PDFFrom a quality standpoint, it is desirable to preserve the characteristics of fresh-cut potatoes at their peak. However, due to the mechanical tissue damage during the cutting process, potatoes are susceptible to enzymatic browning. This study pertains to the selection of the appropriate osmotic dehydration (OD), high pressure (HP), and pulsed electric fields (PEF) processing conditions leading to effective quality retention of potato cuts.
View Article and Find Full Text PDFAbstract: Alternative sweeteners, such as steviol glucosides from the plant Bertoni, are becoming increasingly popular for the design of next-generation foodstuffs. However, the bitter aftertaste of native steviol glucosides is one of the main reasons behind consumer reluctance towards stevia-containing products. Biocatalysis could be a sustainable solution to this problem, through addition of glucosyl moieties to the molecule.
View Article and Find Full Text PDFInnov Food Sci Emerg Technol
July 2022
Pulsed electric field (PEF) and osmotic dehydration (OD) pretreatment can accelerate the time-consuming drying process and minimize its high energy demands. The effect of PEF and OD pre-processing conditions and osmotic solution composition on mass transfer kinetics (water loss, solid gain, water activity) and quality properties (color, texture, total sensory quality) during OD and subsequent air-drying (AD) of pumpkin was studied. Application of PEF (2.
View Article and Find Full Text PDFThe study investigated the effect of active modified atmosphere packaging (20% CO-60% N-20% O) with CO emitters (MAP-PAD) and conventional MAP (MAP) on the quality and shelf-life of gilthead seabream fillets during chill storage, while the most appropriate enzymatic Time Temperature Integrators (TTI) were selected for monitoring their shelf-life at isothermal and variable temperature storage conditions ( = 4.8 °C). The concentration of CO and O in the headspace of the package, volatile compounds and of the microbial population were monitored during storage.
View Article and Find Full Text PDFVitamin C, a water-soluble compound, is a natural antioxidant in many plant-based products, possessing important nutritional benefits for human health. During fruit and vegetable processing, this bioactive compound is prone to various modes of degradation, with temperature and oxygen being recognised as the main factors responsible for this nutritional loss. Consequently, Vitamin C is frequently used as an index of the overall quality deterioration of such products during processing and post-processing storage and handling.
View Article and Find Full Text PDFMultiple factors can directly influence frozen food quality, during processing and post-processing, in the cold chain [...
View Article and Find Full Text PDFThis study investigated the effect of pulsed electric fields (PEF) pretreatment on rehydration kinetics, firmness, and release of intracellular components of dried chickpeas during rehydration at 35 to 65°C. After soaking preconditioning, chickpeas were subjected to PEF treatments (2.5 and 3.
View Article and Find Full Text PDFβ-Galactosidases are key enzymes in the food industry. Apart from the hydrolysis of the saccharide bond of lactose, they also catalyze transgalactosylation reactions, producing galactooligosaccharides (GOS) with prebiotic activity. Here we report the heterologous production in Pichia pastoris of a novel β-galactosidase from the fungus Thermothielavioides terrestris.
View Article and Find Full Text PDFIn the present work a galactomannan extract of low protein residue (< 1.3 % wt dry basis) was isolated from alfalfa (Medicago sativa L.) seed endosperm meal.
View Article and Find Full Text PDFThe rheological and viscoelastic properties of mayonnaise emulsions with different size of oil droplets were investigated. Α programmable rotational rheometer was used for the measurements and flow curves were determined at constant and variable shear rate. Mayonnaise exhibited a non-Newtonian, shear-thinning flow with yield stress and time-dependent features.
View Article and Find Full Text PDFThe objective of this study was the investigation of the effect of variable conditions on quality parameters and the shelf life of fish during frozen storage. Three different fish products were tested, i.e.
View Article and Find Full Text PDFOsmodehydrofreezing (ODF), a combined preservation process where osmotic dehydration is applied prior to freezing, achieves several advantages, especially in plant tissues, sensitive to freezing. OD pre-treatment can lead to the selective impregnation of solutes with special characteristics that reduce the freezing time and improve the quality and stability of frozen foods. ODF research has extensively focused on the effect of the osmotic process conditions (e.
View Article and Find Full Text PDFSystematic kinetic modeling is required to predict frozen systems behavior in cold dynamic conditions. A one-step procedure, where all data are used simultaneously in a non-linear algorithm, is implemented to estimate the kinetic parameters of both primary and secondary models. Compared to the traditional two-step methodology, more precise estimates are obtained, and the calculated parameter uncertainty can be introduced in realistic shelf life predictions, as a tool for cold chain optimization.
View Article and Find Full Text PDFOlive pomace is considered a solid by-product and a rich source of valuable compounds such as polyphenols, flavonoids with antioxidant properties, and proteins. Nonthermal technologies, which cause alterations to cell permeability, are being explored to assist conventional recovery techniques. The aim of this study was to assess the effect of pulsed electric fields (PEF) and high pressure (HP) on improved recovery yield of the high-added-value compounds or to shorten the extraction time of these compounds.
View Article and Find Full Text PDFThe impact of high-pressure (HP) processing on the viability of two probiotic microorganisms ( and ) at varying pressure (100-400 MPa), temperature (20-40 °C) and pH (6.5 vs. 4.
View Article and Find Full Text PDFThe objective of the present study was to investigate the effect of the high pressure (HP) processing and transglutaminase (TGase) treatment of bovine (cow) or ovine (sheep) milk, when applied individually or sequentially, on the quality parameters and anti-hypertensive and immunomodulatory properties of yoghurt. Low-fat (2% w/w) bovine or ovine milk samples were used. Results showed that HP treatment of milk led to acid gels with equivalent quality attributes to thermal treatment, with the more representative attributes being whey separation and firmness, which ranged from 47.
View Article and Find Full Text PDFFresh fish are highly perishable food products and their short shelf-life limits their commercial exploitation and leads to waste, which has a negative impact on aquaculture sustainability. New non-thermal food processing methods, such as high pressure (HP) processing, prolong shelf-life while assuring high food quality. The effect of HP processing (600MPa, 25 °C, 5min) on European sea bass () fillet quality and shelf life was investigated.
View Article and Find Full Text PDFThe aim of this study was to monitor and characterize Greek coffee staling during home storage (secondary shelf life, SSL) using sensory evaluation techniques. Storage temperature (T) and product water activity (a ) are considered as the major factors affecting SSL. Water sorption isotherms fitted to Guggenheim Anderson-de Boer model were used to predict product stability; coffee samples were stable at a < 0.
View Article and Find Full Text PDFAn objective of the present study was the enrichment of skim sheep yoghurt milk base with hydrolysates (WPHs) of whey protein concentrate (WP80) derived from Feta cheesemaking. Moreover, the use of high hydrostatic pressure (HP) treatment at 600 MPa/55 C/10 min as an alternative for heat treatment of milk bases, was studied. In brief, lyophilized trypsin and protamex hydrolysates of WP80 produced under laboratory conditions were added in skim sheep milk.
View Article and Find Full Text PDFIn the present work oil-in-gel (o/g) emulsions comprising 0.4-1% w/w κ-carrageenan in the absence and presence of Ca (20mM) were investigated for their ability to hamper the oxidative degradation under isothermal (5, 20 and 37°C) ambient air storage conditions and promote the in vitro bioaccessibility of β-carotene. The mechanical and structure conformational aspects of the o/g emulsions throughout in vitro digestion were measured by means of oscillatory rheology and optical microscopy.
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