Contents
18.04.2019.
Original scientific paper
Nutritional and antioxidant potential of rice flour enriched with kersting’s groundnut (Kerstingiella geocarpa) and lemon pomace
This study was designed to enhance the nutritional quality, antioxidant properties and product utilization potentials of locally produced ‘Igbemo’ rice flour by adding Kersting’s groundnut and lemon pomace. Kersting’s groundnut is an underutilized legume while lemon pomace is a byproduct of lemon utilization; both meant to enhance the protein quality, antioxidant potential and fibre contents of the composite flour. The dependent variables were minerals composition, amino acid profile, antioxidants and antinutrients properties, in-vitro protein digestibility and in-vitro carbohydrate digestibility. The result showed that blends with higher lemon pomace of 10.00 g had the best calcium, iron, potassium and magnesium contents and antioxidant contents, while blends with highest Kersting’s groundnut (20.00 g) had the best zinc content. The anti-nutrients in the blends were generally low and safe for consumption.
Olugbenga Awolu, Magoh A. Osigwe
01.12.2018.
Professional paper
Development and incorporation of nanoemulsions in food
Currently, nanoencapsulation of bioactive compounds is promising, and is one of the methods that has been proven very effective. The development of food-grade nanoemulsions is in a state of constant innovation due to the interesting features that this method of encapsulation has, such as small droplet size, kinetic stability and appearance. With this technology, it is possible to control some food properties, such as texture, taste and stability. In this article, we present a review of the most commonly used methods in the creation of nanoemulsions, the recent developments of these dispersions, the relevant applications of nanoemulsions in food matrices, the most commonly used food-grade materials and the functionality of nanoemulsions, which are designed primarily to encapsulate compounds with biological activity. Nanoemulsions have been shown to be effective in preventing degradation and improving the bioavailability of bioactive compounds, such as oil-soluble vitamins, antimicrobials, flavours and antioxidants. At the end of this article, facts of interest about acceptance issues and nanotechnology regulatory policies in the food industry are presented.
Antonio de Jesus Cenobio-Galindo, Rafael G. Campos-Montiel, Rubén Jiménez-Alvarado, Isaac Almaraz-Buendía, Gabriela Medina-Pérez, Fabián Fernández-Luqueño
01.12.2018.
Professional paper
Effects of “starch:water” ratio on gelatinization of pinhão starch from nine germplasm collections, measured by Differential Scanning Calorimetry
Native starch was extracted from nine germplasm collections of Araucaria angustifolia seeds in aqueous medium and they were characterized by Pasting Properties (RVA), X-ray Powder Diffractometry (XRD) and Scanning Electron Microscopy (SEM). The gelatinization process of each sample was evaluated at different ratios of starch:water by Differential Scanning Calorimetry (DSC). A slight displacement in the gelatinization curves was observed for the pinhão starches prepared with different amounts of water. With an increase in water content, most of the samples presented a decrease in the peak, the conclusion temperatures, and the range of gelatinization temperatures, while the enthalpy did not follow a standard behavior. A displacement or a narrowing of the gelatinization temperature range occurred with increasing water content. Pinhão starch showed pasting temperature in the range of 60-67 °C and there were differences in the pasting properties and degree of relative crystallinity between the analyzed samples. The C-type diffraction pattern was found for all the samples and the morphology of starch granules was similar, with oval and round shapes. Therefore, different characteristics were found among starches from nine germplasm collections, encouraging the protection of the biological diversity of selected species, aiming at future applications.
Camila D. Bet, Rossane C. B. Godoy, Layse P. Cordoba, Ivo M. Demiate, Luiz G. Lacerda, Egon Schnitzler
18.04.2018.
Original scientific paper
Fermentation of tender coconut water by probiotic bacteria Bacillus coagulans
Coconut water is currently being considered as an elixir for patients suffering from diseases like dengue and malaria as well as chikungunia to provide hydration properties to the body. It has become a popular beverage for many people owing to its palatability and high mineral content. In this study, the growth, survival and fermentation performance of the probiotic bacterium Bacillus coagulans in coconut water was assessed in order to produce a novel non-dairy, probiotic beverage. The species was characterized on the basis of morphology, physiology and biochemical parameters and its probiotic attributes were assessed. Batch fermentations were carried out for 2 days at a constant 37°C, thereafter the samples were subjected to microbiological and chemical analysis. The results suggested that the specie produced lactic acid and was acid and bile tolerant. The pH and titratable acidity of probiotic fermented coconut water were found to be 4.4 and 0.53 % lactic acid, respectively. The viscosity of fermented coconut water increased significantly from an initial 5.13 mPa.s to 5.35 mPa.s because of the increase in soluble solids content due to exopolysaccharide production by B. coagulans during fermentation. Also, the overall acceptability score of probiotic coconut water was higher than tender coconut water, suggesting its feasibility for use as a probiotic beverage.
Aishwarya Singh Gangwar, Aastha Bhardwaj, Vasudha Sharma
18.04.2018.
Original scientific paper
Examination of optimum test conditions for a 3-point bending and cutting test to evaluate sound emission of wafer during deformation
The purpose of this study was to investigate optimum test conditions of acoustical-mechanical measurement of wafer analysed by Acoustic Envelope Detector attached to the Texture Analyser. Forcedisplacement and acoustic signals were simultaneously recorded applying two different methods (3-point bending and cutting test). In order to study acoustical-mechanical behaviour of wafers, the parameters “maximum sound pressure”, “total count peaks” and “mean sound value” were used and optimal test conditions of microphone position and test speed were examined. With a microphone position of 45° angle and 1 cm distance and at a low test speed of 0.5 mm/s wafers of different quality could be distinguished best. The angle of microphone did not have significant effect on acoustic results and the nu
ERDEM CARSANBA, Gerhard Schleining
01.12.2017.
Professional paper
Quality assessment and shelf life modeling of pulsed electric field pretreated osmodehydrofrozen kiwifruit slices
The objective of this workwas to investigate the potential use of pulsed electric field (PEF) in combination with osmotic dehydration (OD) as a pre-freezing step and to evaluate the effect on quality characteristics and shelf life of frozen kiwifruit. Peeled kiwifruit was subjected to PEF (1.8 kV/cm), sliced and treated in OD-solution [containing glycerol, maltodextrin, trehalose, ascorbic acid, calcium chloride, citric acid, sodium chloride; 1/5 (wfruit/wsolution)] for 30 and 60 min at 35 °C. Combined, PEF only and OD only treated samples as well as nontreated and blanched (80 °C, 60 s) samples were frozen and stored at constant (-5, -10, -15, -25 °C) and dynamic temperature conditions (-18 °C-3 d, -8 °C-2.5 d, -15 °C-3 d). Quality of frozen samples was evaluated by means of drip loss, colour, texture, vitamin C and sensory evaluation (1-9 scale); and shelf life (SL) was calculated. Nontreated and blanched samples presented high drip loss and tissue softening (instrumentally measured as Fmax decrease). The tissue integrity was well retained in all osmotically pretreated samples. PEF pretreatment caused increase of fruit whiteness (increase of L value) and yellowness (a and/or b value increase); SL calculation was based on colour change. All OD samples had high vitamin content (24.6 mg/100 g fresh material compared to 138-154 mg/100 g osmodehydrated material); PEF led to 93% (of the initial) vitamin retention; blanched samples showed the lowest retention (86.9% of the initial) (criteria for SL calculation). OD and combined PEF-OD treatment increased the shelf life of frozen kiwifruit (up to 3 times; based on sensorial criteria). The developed kinetic models for colour change, vitamin loss, and sensory quality deterioration were validated at dynamic temperature conditions. PEF pretreated OD (at significantly shorter time, 30 min compared to 60 min) kiwifruits retained optimum quality and sensory characteristics. PEF and OD could be used as a preprocessing step of good quality, longer shelf life kiwi sliced frozen products.
Efimia Dermesonlouoglou, Ismini Zachariou, Varvara Andreou, Petros S. Taoukis
01.12.2017.
Professional paper
Effect of storage time and gamma irradiation on the chemical properties of olive (Olea europaea) oils
The objective of this study was to investigate the effects of gamma irradiation at doses of 0, 1, 2 and 3 kGy, and storage time of olive fruits for 0, 30 and 45 days on changes in chemical properties of olive oil during storage periods of 0, 6 and 12 months. The initial acidity value (AV), peroxide value (PV), Thiobarbituric Acid (TBA), phenolic content, iodine value (IV), and saponification value (SV) of virgin olive oil obtained from olives fruits immediately after harvest (at day zero) were 1.04%, 3.06 mEqO2 kg-1oil, 0.025 mg MDA kg-1 oil, 314.71 mg gallic acid kg-1 oil, 93.38 gI2 100 g-1 oil and 194.88 mg KOH g-1 oil, respectively. In general, the AV and PV of olive oil was increased by gamma irradiation, while the phenolic and IV of olive oil was deceased by gamma irradiation and storage time. The TBA value and SV of olive oil was not significantly (p>0.05) changed by gamma irradiation.
M. Al-Bachir
01.12.2017.
Professional paper
Food oral processing in humans: links between physiological parameters, release of flavour stimuli and flavour perception of food
In humans, food oral processing (FOP) is the first step in the digestive process. It prepares the food for swallowing and to undergo the process of digestion. During chewing, the food is comminuted by the combined action of chewing and saliva to form a bolus. The particle size of the bolus is reduced due to the action of the tongue and the teeth, and the saliva is continuously produced by the salivary glands to humidify and impregnate the food. Saliva lubricates the bolus and enables the cohesion of particles to prepare for swallowing. During food oral processing, the compounds responsible for food flavour and taste are released, leading to the perception of food organoleptic properties and significantly contributing to the consumer’s acceptability of the product. Understanding this process of food breakdown and bolus formation thus appears to be a way to revisit food functional properties. However, this process is extremely complex, and as such, its description necessitates a combination of many quantities from different disciplines, i.e., physics, chemistry, physiology, psychology, behavioural science and food science. It depends, on one hand, on food properties and on the other hand, it depends on oral physiology. However, large inter-individual variability is commonly observed, which has important consequences on flavour release and perception. The challenge for the food industry is to be able to develop food considering this large variability, and sensory and nutritional constraints. This challenge is particularly relevant when specific populations (i.e., elderly, infants or obese subjects) are considered.
Gilles Feron, Christian Salles
01.12.2017.
Professional paper
Estimating the risk of phthalates exposure via tea consumption in general population
Four common phthalic acid esters (PAEs) levels in tea fusions samples prepared from three types of tea bags (green, black and white) of ten commercial brands were extracted from the infusions by a dispersive liquid-liquid micro extraction method and determined by GC-MS.PAEs were not found in white tea samples. Residue levels of total phthalic acid esters (TPAEs) in black and green teas showed no significant difference (median=367.5, Interquartile range=244.7-667.5 and median=381, Interquartile range=188.7-688.2µg/kg respectively). DEHP levels in green teas were significantly higher than those in black teas (Median= 93.5 and 204 respectively). Total phthalate esters (TPAEs) levels in flavored teas were about two-fold higher than in non-flavored teas. The four commercial brands tested contain significant levels of DEHP when compared to other brands. Essential oils and essences that were added to tea for improvement of color and taste could be the main sources of PAEs contamination. If oral absorption of phthalates were assumed to be 100%, the maximum daily exposure levels to TPAEs via tea consumption (due to consumption of 5 cups of tea prepared from the tea containing the highest levels TPAEs) were estimated to be 230e-4 μg/kg bw/Day, which are far lower than the regulation levels set by the expert panels on regularly toxicity.
Mohammad Mehdi Amin, Foruz Rastegari, Parinaz Poursafa, Karim Ebrahim
01.12.2017.
Professional paper
Optimization of osmotic dehydration of chestnut (Castanea sativa Mill.) slices using Response Surface Methodology
Osmotic dehydration of chestnut slices in sucrose was optimized for the first time by Response Surface Methodology (RSM). Experiments were planned according to a three-factor central composite design (α=1.68), studying the influence of sucrose concentration, temperature and time, on the following parameters: volume ratio, water activity, color variation, weight reduction, solids gain, water loss and normalized moisture content, as well as total moisture, ash and fat contents. The experimental data was adequately fitted into second-order polynomial models with coefficients of determination (R2) from 0.716 to 0.976, adjusted-R2 values from 0.460 to 0.954, and non-significant lacks of fit. The optimal osmotic dehydration process conditions for maximum water loss and minimum solids gain and color variation were determined by the “Response Optimizer” option: 83% sucrose concentration, 20 °C and 9.2 hours. Thus, the best operational conditions corresponded to high sugar concentration and low temperature, improving energy saving and decreasing the process costs.
Teresa Delgado, Bruna Paim, José Alberto Pereira, Susana Casal, Elsa Ramalhosa
