Clarification of <Emphasis Type="Italic">Jerusalem Artichoke</Emphasis> Extract Using Ultra-filtration: Effect of Membrane Pore Size and Operation Conditions

Jerusalem artichoke is an important plant for industrial inulin production. Jerusalem artichoke extract was clarified by ultra-filtration. Tests were performed to investigate effects of membrane pore size and operation conditions (trans-membrane pressure and rotation speed) on filtration kinetics and membrane-fouling mechanism. Membrane fouling was proved the main filtration resistance for a 20-kDa membrane, while concentration polarization-induced resistance was dominant for 30-, 50-, and 100-kDa membranes. Despite their similar filtration behavior, the 50-kDa membrane, compared to the 100-kDa membrane, led to less protein content (impurity) in the filtrate. Studies with the rotation speed varied from 0 to 1600 rpm and trans-membrane pressure from 0.2 to 0.4 MPa demonstrated that stirring was essential for elimination of membrane fouling. Competition of driving force and fouling was justified when trans-membrane pressure increased from 0.3 to 0.4 MPa. Filtrate analysis including protein removal, turbidity, and inulin purity revealed that ultra-filtration using the 50-kDa membrane with a trans-membrane pressure of 0.3 MPa and a rotation speed of 800 rpm was able to clarify the Jerusalem artichoke extract, removing 99% protein, and obtain a filtrate with inulin purity of 98%.     

Eliciting the Sensory Modalities of Fat Reformulated Yoghurt Ice Cream Using Oligosaccharides

In the present work, fat reduction of Greek strained yoghurt ice cream (YIC) was carried out in three proportional milkfat levels i.e. 30, 50 and 70% using three types of oligosaccharides namely long-chain inulin, oligofructose and maltodextrin 12 DE. Greek strained yoghurt was blended with ice cream mixes in ratios of 1:3 and 1:1. The physico-chemical, textural and thermal characteristics of the YIC mixes and their obtained frozen end products were determined. The sensory modalities (olfactory, gustatory, tactile and oro-tactile) of the YIC were monitored following 2 and 16 weeks of quiescent frozen storage at ?25 °C. Milkfat reduction impaired significantly (p?<?0.05) the perceived creaminess and mouthcoating sensation stimuli, whist it intensified the oral tissue friction associated sense stimuli such as astringency, wateriness and coarseness. Long-chain inulin- and maltodextrin-based samples received the highest scores for creaminess, mouthcoating, gumminess, hardness and iciness. The increase of the yoghurt to ice cream mix ratio escalated the friction/recrystallization-associated sensations e.g. astringency, sourness, coarseness and wateriness. Notwithstanding yoghurt supplementation reinforced the pseudoplasticity and macroviscosity of the ice cream mixes, it suppressed their aeration capacity leading to heavy-bodied ice creams. However, no significant effects of yoghurt supplementation level on the colligative and meltdown rate of the YIC formulations were identified. Partial least squares coupled discriminant analysis (PLS-DA) revealed that fat reformulation of YICs using oligosaccharides results in a substantially diversified sensory profile. Generally, a 50% fat reduction of YICs using long-chain oligosaccharides appears to be a technologically tangible solution.     

Decision Support for the Comparative Evaluation and Selection of Analytical Methods: Detection of Genetically Modified Organisms as an Example

The selection of the best-fit-for-purpose analytical method to be implemented in the laboratory is difficult due to availability of multiple methods, targets, aims of detection, and different kinds and sources of more or less reliable information. Several factors, such as method performance, practicability, cost of setup, and running costs need to be considered together with personnel training when selecting the most appropriate method. The aim of our work was to prepare a flexible multicriteria decision analysis model suitable for evaluation and comparison of analytical methods used for the purpose of detecting and/or quantifying genetically modified organisms, and to use this model to evaluate a variety of changing analytical methods. Our study included selection of PCR-, isothermal-, protein-, microarray-, and next-generation sequencing-based methods in simplex and/or multiplex formats. We show that the overall result of their fitness for purpose is relatively similar; however, individual criteria or a group of related criteria exposed more substantial differences between the methods. The proposed model of this decision support system enables easy modifications and is thus suitable for any other application of complex analytical methods.     

Starch retrogradation and its impact on nutritional starch fractions in plantain (<Emphasis Type=Italic>Musa AAB</Emphasis>) foods

Starch retrogradation in plantain starch was studied by an enzymatic method and X-ray diffraction analysis. The enzymatic method and X-ray diffraction gave comparable results. Retrograded starch (RS3) and physically trapped starch (RS1) contents of plantain foods were subsequently determined by the enzymatic method. RS3 content of 5.0 ± 0.9 to 13.2 ± 3.0 g/100 g dry weight basis was obtained for unripe samples while a value ranging from 0.9 ± 0.4 to 2.5 ± 0.9 g/100 g was obtained for ripe samples. Retrogradation increased slowly digestible starch (SDS) and physically inaccessible starch (RS1) portions in some of the samples but not in others. Retrogradation resulted in an increase in the quantity of SDS for ripe plantain samples. In unripe plantain samples cooked without salt, there was a significant increase (p ≤ 0.05) in the value of RS1 from 4.6 ± 3.6 to 7.7 ± 2.0 g/100 g after 48 h of cold storage but no significant change for samples cooked with salt.     

Modelling mechanical properties of spruce and Douglas fir timber by means of X-ray and grain angle measurements for strength grading purpose

This study proposes a model using data from a scanner (X-ray and grain angle measurements) to perform strength grading. The research also includes global measurements of modulus of elasticity (obtained by vibrations and ultrasound methods), static bending stiffness and bending strength of 805 boards of Douglas fir and 437 boards of spruce. This model can be used in an industrial context since it requires low computational time. The results of this study show that the developed model gives better results than the global non-destructive measurements of the elastic modulus commonly used in the industry. It also shows that this improvement is particularly higher in the case of Douglas fir than for spruce. The comparison has been made on both the quality of the mechanical properties assessment and on the improvement of the grading process according to the European standards by using different index.     

Effect of sodium selenite on the bacteria growth,selenium accumulation,and selenium biotransformation in <Emphasis Type="Italic">Pediococcus acidilactici</Emphasis>

In this study, the effect of low selenium concentrations on bacteria growth, selenium bioaccumulation, and selenium speciation in Pediococcus acidilactici was investigated. Six different sodium selenite (Na₂SeO₃) solutions with concentrations of 0, 0.5, 1, 2, 3, and 4 mg/L were added in MRS broth for 24 h. Then, the obtained bacterial pellets were weighed. The contents of total selenium and selenium species in the bacterial pellets were measured via optimized enzymatic hydrolysis and HPLC-ICP-MS. The maximum dried P. acidilactici biomass of 1.44 g/L was achieved by utilizing 1 mg/L Na₂SeO₃. By increasing sodium selenite concentrations, total selenium contents were significantly increased from 0.14 to 1.45 mg/g dry weight (p < 0.05). The findings indicated that selenium was favorably incorporated into the bacteria protein fraction and mainly formed selenocysteine. Therefore, selenium-enriched lactic acid bacterium P. acidilactici can deliver a less-toxic, more bioavailable selenium source for human and animal nutrition.     

Physicochemical and pasting properties of maize flour as a function of the interactive effect of natural-fermentation and roasting

The effect of natural-fermentation and roasting on maize physicochemical and functional properties were evaluated. Natural fermented maize seeds were soaked for variable times (0, 24 and 48 h) and directly decorticated or roasted before milling into flour. Generally during the 24 to 48 h natural fermentation, total sugars (80.3–92.0 g/100 g) and proteins contents (4.0–7.6 g/100 g) decreased while they significantly increased with soaking. Soluble sugars content of the unroasted maize significantly decreased with fermentation while that of roasted maize significantly increased. Reverse observations were made on soluble proteins. The antinutrients (phytates and total polyphenols) contents of the grains as well as the functional properties of their flours were observed to have been significantly changed following fermentation and roasting. In particular the least gelation concentration (6 to 18 g/100 mL), an important reverse index of gelating power significantly increased with fermentation and roasting. As consequence the viscosity of the fermented maize flours were systematically significantly lower than that of the unfermented flour. Generally while the effects of duration of fermentation and roasting on the viscosity were not consistent, the 48 h natural fermented and roasted flour was observed to particularly produce flours of much lower viscosity. This highlighted the positive effect of combining fermentation and roasting to improve the quality of weaning flour made from maize.     

Antioxidant activity,phenolic, carotenoid and color changes in packaged fresh carrots stored under refrigeration temperature

Carrots of uniform size were wrapped tightly within a plastic cling film and stored under refrigeration conditions for a period of 24 days. The roots were analyzed for changes in phenolics, carotenoids, antioxidant activity, texture and optical properties at every 6th day. Total carotenoid levels decreased from 12.68 to 8.17 mg/100 gm during the storage and a similar change in phenolics was observed with values decreasing from 41.63 to 32.31 mg GAE/100 gm. Collective losses of both carotenoids and phenolics negatively affected antioxidant activity in carrots with figures decreasing from 16.50 to 11.07%. The refrigeration storage of carrots also had an influence on its optical and textural characteristics at significant levels (p?<?0.5). Texture change in carrots was more profound in core sections of root during the storage. A strong positive correlation was observed for antioxidants with carotenoids, phenolics, L* and a* values.     

Isotopic and Elemental Authenticity Markers: a Case Study on Cypriot Wines

This study monitors variations in isotopes and elements in relation to grape variety, environmental factors and provenance in order to address the wine authenticity issue. Inductively coupled plasma atomic emission spectroscopy (ICP-AES) assessed the wines’ elemental content. Site-specific nuclear isotope fractionation-nuclear magnetic resonance and isotope ratio mass spectrometry methodologies determined in authentic and commercial wines the distribution of the naturally occurring stable isotopes of the deuterium/hydrogen (D/H) ratios and carbon (¹³C/¹²C) in ethanol of wine and oxygen ratio (¹⁸O/¹⁶O) in wine water. Chemometrics delineated the elements and isotopes responsible for wine classification. Specifically, unsupervised principal component analysis (PCA) framed the importance of grape variety and provenance, while supervised analysis pinpointed the vineyard effect and highlighted the contribution of the vintage year. Validation steps ensured that the extracted models do not predict randomly and their results are reliable. In fact, the acquired results can be incorporated to the EU Wine Isotopic Databank database providing both a guide and a tool for eventual candidatures for denomination of origin and support both Cypriot wine and winemakers. In this context, this research contributes to authenticity assurance of wines and adds value to final products, while it helps controlling hazards arising from environmental changes.     

Optimization of Microwave-Assisted Extraction of Polyphenolic Compounds from <Emphasis Type="Italic">Ocimum basilicum</Emphasis> by Response Surface Methodology

Microwave-assisted extraction (MAE) was optimized by response surface methodology in order to enhance the extraction of polyphenols from basil (Ocimum basilicum L). Box–Behnken experimental design on three levels and three variables was used for optimization. Influence of ethanol concentration (50, 70, and 90%); microwave power (400, 600, and 800 W); and extraction time (15, 25, and 35 min) on each response were investigated. Experimental results were fitted to a second-order polynomial model, and multiple regression analysis and analysis of variance were used to evaluate model fitness and optimal conditions. Considering the maximum content of extracted total phenols, total flavonoids, and antioxidant activity, the optimal conditions for all investigated response were ethanol concentration of 50%, microwave power of 442 W, and extraction time of 15 min. Under the optimal conditions, obtained basil liquid extract contained 4.299 g gallic acid equivalents/100 g dry weight (DW) of total polyphenols, 0.849 g catechin equivalents/100 g DW of total flavonoids, and IC₅₀ and EC₅₀ values of 9.602 and 82.889 μg/mL, respectively. The development of simultaneous MAE procedure for extraction of total phenols, total flavonoids, and potential antioxidants from basil, represented valorization of basil as valuable source of bioactive compounds.