Use of rosemary extract in preventing oxidation during deep-fat frying of potato chips

The effect of using a rosemary extract on the stability of oil used for frying potato chips has been evaluated. Sliced potatoes were fried intermittently in soybean oil containing a natural extract from rosemary. The conditions used for frying were 185°C for 90 s. Two separate experiments, with and without replenishment of oil, were carried out. Oil samples were taken each day, not only from the frying pans but also by extraction with hexane from the chips. Changes in the induction period of the oil samples (Rancimat method) were determined. The induction period decreased as frying progressed. The reduction in the induction period was higher in the oil free of rosemary extract, and the chips were much darker in color. The oil containing the extract showed greater antioxidant activity, and reduced darkening and rancidity of the oil. Potato chips fried in the oil with added rosemary extract were more acceptable than chips fried in oil containing no extract until the last frying. The free radical scavenging activity of rosemary extract in comparison to other natural antioxidants was also determined by the reduction of O₂ ^.- in a hypoxanthine/xanthine oxidase system.     

Addition of yogurt to wort for the production of spirits: Evaluation of the spirit aroma over a two-year period

Triggered by the development of lactic acid bacteria (LAB) during the production of Scotch whisky, this study examined the influence of yeast and LAB inoculation on whisky flavor. Four new spirits were produced using the same process. LAB were added as a form of a Greek yogurt's live culture. In each category (barley and rye), one sample was fermented with Greek yogurt while the other was fermented without it. The spirits were matured and analyzed at five different points. Results from gas chromatography-mass spectrometry (GC-MS) analysis showed basic volatile compounds, along with some important extra compounds with yogurt culture. The most obvious differences were observed in the concentration of butanoic acid, a characteristic acid in spirits undergoing lactic acid fermentation: to identify esters such as ethyl butanoate, ethyl isobutanoate, isoamyl butanoate, and 2-phenylethyl butanoate, they are not typical compounds in whisky.     

Full Characterisation of Crambe abyssinica Hochst. Seed Oil

This work was dedicated to reporting the full chemical and physical characterisation of Crambe abyssinica Hochst. seed oil. The oil from the seeds was extracted using n-hexane. The seeds contain about 30?% oil. Density, refractive index, colour, smoke point, viscosity, acidity, saponification value, iodine value, fatty acid methyl esters, the relative position of fatty acids in C₁ and C₃ carbon glycerol, sterols, tocopherols, peroxide value, $ \mathop E\nolimits_{{1{\text{cm}}}}^{1\,\% } $ at 232?nm, and the susceptibility to oxidation measured by the Rancimat method were determined. The oil was found to contain high levels of unsaturated fatty acids, especially C22:1 (63.77?%). The dominant saturated acid was C22:0 (2.14?%). The oil was also found to contain high levels of β-sitosterol (51.93?%), campestanol (21.98?%), and brassicasterol (12.35?%). α-, γ-, and δ-Tocopherols were detected up to levels of 7.67, 125.04, and 3.99?mg/kg, respectively. The induction period (at 110?°C and 20?l/h) of the oil was 8.83?h. The relative position of fatty acids in C₁ and C₃ position was as follows: linoleic 0.45?%, oleic 8.84?%, and erucic 90.72?%. The thermal profile of the oil presented a single peak at ?20.94?°C.     

Detection of olive oil adulteration using principal component analysis applied on total and regio FA content

Principal component analysis (PCA) has been used to establish a new method for the detection of olive oil adulteration. The data set, composed of values obtained from the determination of the mole percentage of total FA and their regiospecific distribution in positions 1 and 3 in TG of oils (pure or mixtures) by GC analysis, was subjected to PCA. 3-D scatter plots showed clearly that it is possible to distinguish the pure oils from the mixtures. Moreover it is possible to discriminate the different types of seed oil used for the adulteration.     

Recovery of Natural Antioxidants from Olive Mill Wastewater Using Genapol-X080

The possibility of applying cloud point extraction (CPE) using Genapol X-080 as surfactant for the separation of phenolic compounds from olive mill wastewater was examined. The ability of the surfactant to recover individual and mixtures of polyphenols and tocopherols in various concentrations from aqueous solutions was tested before its application for the recovery of phenols from olive mill wastewater. Many of the examined individual polyphenols were recovered at high percentage. Especially, in the case of Luteolin, low surfactant concentrations were sufficient for quantitative removal. The recovery appeared proportional to the surfactant concentration. The complete recovery of tocopherols was also possible. Total phenol recovery by simple and successive CPE of olive mill wastewater with various concentrations (2, 5 and 20%, v/v) of Genapol X-080 was up to 89.5%.     

Qualitative and Quantitative Detection of Protein and Genetic Traits in Genetically Modified Food

Due to the market introduction of genetically modified organisms (GMOs) in crops, foods, and ingredients, legislation worldwide came face to face with the question of the use and labeling requirements on GMO crops and their derivatives. In this review, protein- and DNA-based methods, such as enzyme-linked immunosorbent assay, western blots, and qualitative and quantitative polymerase chain reaction PCR (Q-PCR) are reviewed. Qualitative detection methods for genetically modified (GM) sequences in foods have evolved rapidly during the past years. The sensitivity of these systems is extremely high, even for processed foodstuffs. However, the availability of quantitative detection methods for GMO analysis is an important prerequisite for the introduction of threshold limits for GMOs in food. The recently introduced labeling threshold for GMOs in food ingredients by the European Union has forced official food control laboratories to apply quantitative PCR methods. Taking the precision of quantitative PCR detection methods into account, suitable sample plans and sample sizes for GMO analysis are discussed. As quantitative GMO detection methods measure GMO contents of samples in relation to reference material, priority must be given to international agreements and standardization on certified reference materials. The rapidly increasing number of GM foods on the market demands the development of more advanced multidetection systems, such as microarray technology. Challenges and problems arising from the inability to detect GM foods for which the modified sequence is unknown, the lengthy standardization procedures, and the need to continuously update databases comprising commercially available GM foods and the respective detection strategies are also discussed.     

Wine produced by immobilized cells on dried raisin berries in sensory evaluation comparison with commercial products

Comparative sensory evaluation of wines produced by immobilized cells of Uvaferme 299 on dried raisin berries and free cells using the Saint Denis grape variety and of commercial Greek products (‘Biblia Chora’ rosé wine produced from the Syrah grape variety, ‘Palivos’ and ‘Strofilia’ rosé wines both produced from the Agiorgitiko grape variety) was carried out. Sensory evaluation was conducted twice by 11 tasters previously trained and a method for panel validation was proposed. Subsequently, the wines were evaluated for their aroma intension, aroma complexity, aroma elegance and overall quality. Duncan's multiple range test clearly showed that there were statistically significant differences between wines produced using different grape varieties and fermentation conditions. Linear regression analysis of the results was performed in order to investigate which sensory parameter had a significant effect on the overall quality and it revealed that only aroma elegance affected significantly the overall quality. Wine produced by immobilized cells scored a statistically higher value for its overall quality than the wine produced by free cells. Finally, discriminant sensory evaluation revealed a gooseberry, cherry, mint aroma for ‘Biblia Chora’ wine and a citrus, rose aroma for ‘Strofilia’ and ‘Palivos’ wines. Wines produced using immobilized and free cells were characterized by a fruity, banana‐like aroma, and a herbaceous note was predominant. Copyright © 2005 Society of Chemical Industry     

Storage of olives (Olea europaea) under CO2 atmosphere: Effect on anthocyanins,phenolics, sensory attributes and in vitro antioxidant properties

Green, unripe olives were subjected to post-harvest treatment under a CO₂ atmosphere for a period of 12 days. The total polyphenol (TP), total flavonoid (TFd) and total anthocyanin (TA) contents, along with the antioxidant and sensory characteristics, were continuously monitored during the treatment on a 24 h-interval basis, in order to identify possible changes in the quality of olives related mainly to changes in the polyphenolic contents. The storage of olives under CO₂ atmosphere resulted in pronounced increases in TP and TF contents, mainly within the first 3-5 days, but TA exhibited a different pattern of evolution. Furthermore, storage under CO₂ contributed to flavour appearance with the development of fruity/floral notes, and reduced bitterness. The in vitro antioxidant properties of the CO₂-treated sample showed notable increases compared with the sample stored under regular atmospheric conditions. It was concluded that storage of olives under a CO₂ atmosphere resulted in the appearance of desired sensory attributes, by decreasing bitterness and developing aroma and colour, and the functional (antioxidant) properties were improved. This approach may be used as an alternative, chemical-free means of table olive debittering.