Vegetables are a natural source of bioactive compounds, however, their content is strongly affected by the preparation methods. The study aimed to find the balance between high health-promoting ...properties, resulting from well-retained minerals content, and sensory properties by testing different times of sous-vide cooking of vegetables at 85 °C. For each vegetable, broccoli, green beans and beetroots, three times options of sous-vide treatment were individually applied. No effect of sous-vide cooking on dry matter content was found for tested vegetables, with the exception of dry mass loss of beetroots cooked for 180 min. The results of potassium, magnesium, calcium and phosphorus determination, confirmed that the sous-vide technique often allows for the retention of these minerals at a level not lower than in raw vegetables. For both broccoli and beetroots, it was observed that the longer the sous-vide processing time, the lower the color intensity, and in the case of each tested vegetable, the worse the consistency. Therefore, the study proves that this method of heat treatment reduces the loss of minerals and preserves the desired color of studied vegetables.
Lactic acid fermentation represents the easiest and the most suitable way for increasing the daily consumption of fresh-like vegetables and fruits. Literature data are accumulating, and this review ...aims at describing the main features of the lactic acid bacteria to be used for fermentation. Lactic acid bacteria are a small part of the autochthonous microbiota of vegetables and fruits. The diversity of the microbiota markedly depends on the intrinsic and extrinsic parameters of the plant matrix. Notwithstanding the reliable value of the spontaneous fermentation to stabilize and preserve raw vegetables and fruits, a number of factors are in favour of using selected starters. Two main options may be pursued for the controlled lactic acid fermentation of vegetables and fruits: the use of commercial/allochthonous and the use of autochthonous starters. Several evidences were described in favour of the use of selected autochthonous starters, which are tailored for the specific plant matrix. Pro-technological, sensory and nutritional criteria for selecting starters were reported as well as several functional properties, which were recently ascribed to autochthonous lactic acid bacteria. The main features of the protocols used for the manufacture of traditional, emerging and innovative fermented vegetables and fruits were reviewed. Tailored lactic acid bacteria starters completely exploit the potential of vegetables and fruits, which enhances the hygiene, sensory, nutritional and shelf life properties.
► Exploitation of vegetables and fruits through lactic acid fermentation. ► Criteria for selecting starters include technological and functional properties. ► The advantages of using autochthonous starters were described. ► Emerging and traditional fermented vegetable and fruit products were also reviewed.
In recent decades, the concern over depletion of the world׳s petroleum reserves and environmental pollution has increased the demand to develop a renewable and environmental friendly fuel. Biodiesel, ...which mainly consists of Fatty Acid Methyl Esters (FAME) is one of the best substitutes for diesel fuel. Currently, vegetable oils, edible or non-edible, are the main resources of biodiesel. This review aims at providing comprehensive information and analyzes on biodiesel produced from edible and non-edible vegetable oils, their composition and specifications. Accordingly, the Fatty Acid (FA) profiles of 28 edible vegetable oils and 40 non-edible vegetable oils were collected. Their main specifications including sulfur content, density, viscosity, flash point, cloud point, pour point, cold filter plugging point, cetane number, iodine number, heating value, acid value and carbon residual before and after transesterification (vegetable oil and biodiesel, respectively) were analyzed in detail.
Many researchers have developed prediction models to quantify biodiesel specifications to optimize its manufacturing and obtain biodiesel with the best specifications. Three factors that are especially influential are the fatty acids profiles, the degree of unsaturation within the FA structures and molecular weight. Accordingly, many models have been constructed on these features. There are also models that quantify the relationship between the biodiesel specifications and its thermodynamic properties or other specifications. Accordingly, the second part of this work was conducted on the existing prediction models. All the models were discussed along with their deviation in prediction.
Background and Aims Rocket salad (Eruca sativa Mills) is one of the major leafy vegetables produced worldwide and has been characterized as a rich source of chemoprotective glucosinolates (GSL). The ...relationship between N fertilization and the resulting plant biomass and N status with GSL quantity and quality in rocket leaves was examined. Methods A pot experiment was conducted, applying ten different N-rates and destructive sampling was carried out 15, 30 and 45 days after transplanting (DAT). The Mitscherlich equation was used to establish NO.sub.3-N critical levels at each growth stage and as an indicator of N demand for relative maximum dry matter accumulation and glucosinolate content and composition was determined. Results Glucosinolate content was significantly influenced by N rate, growth stage and their interaction. Different GSL types showed dissimilar responses to N fertilization: aliphatic GSLs were significantly reduced under increased N rates whereas indole GSL showed the reverse. Under excess N fertilization (>1.04 g/plant), dry matter accumulation remained constant, NO.sub.3-N was significantly increased and total GSL content was significantly reduced, factors that could lead to an anticipated product quality decline. Conclusions The application of the critical NO.sub.3-N level approach used to identify optimal N fertilization rates for plant growth could serve as means to obtain optimized GSL content in the edible plant parts. Keywords Eruca * Glucosinolates * N critical levels * Nitrate environmental pollution * Plant product quality
► Level of eight heavy metals was determined in vegetables irrigated with wastewater. ► Heavy metals accumulation was several folds greater than the FAO/WHO standards. ► High bioconcentration factor ...was associated with all vegetables studied. ► Daily human intake of the metals a was significantly greater than FAO/WHO standards.
Green vegetable crops irrigated with wastewater are highly contaminated with heavy metals and are the main source of human exposure to the contaminants. In this study accumulation of eight heavy metals (Cu, Ni, Zn, Cr, Fe, Mn, Co and Pb) in green vegetables like Allium cepa, Allium sativum, Solanum lycopersicum and Solanum melongena, irrigated with wastewater in Mardan are studied using Atomic Absorption spectrophotometer. The studied metals in vegetable grown on wastewater irrigated soil were significantly higher than those of tube well water irrigated soil and WHO/FAO permissible limits (P<0.05). The most heavily contaminated vegetable was wastewater irrigated A. cepa, where the accumulation of Mn (28.05mgkg−1) in the edible parts was 50-fold greater than A. cepa irrigated with tube well water irrigated soil. It may be concluded that both adults and children consuming these vegetables grown in wastewater irrigated soil ingest significant amount of these metals and thus can cause serious health problems.
Glucosinolates are secondary metabolites of almost all plants of the order Brassicales, and have been known to control nematode populations. In this study, 14 glucosinolates were identified, ...quantified, and compared in several varieties and cultivars of cruciferous plants including Brassica campestris ssp. pekinensis (Chinese cabbage), Brassica juncea var. crispifolia L. H. Bailey (mustard), Brassica juncea L. Czern. var. juncea (leaf mustard), Brassica oleracea L. var. acephala (kale), Raphanus sativus L. (radish), and Brassica campestris L. ssp. oleifera (winter turnip rape). The most abundant glucosinolate in mustard, leaf mustard, kale, and radish was sinigrin. In leaf mustard, the sinigrin content ranged from 193.05 μmol/g to 215.52 μmol/g, and in mustard, the sinigrin contents of blue mustard and red mustard were 219.08 μmol/g and 215.73 μmol/g, respectively. Kale and radish contained 137.79 μmol/g and 120.25 μmol/g, respectively, of sinigrin. Gluconapin was the most abundant glucosinolate in winter turnip rape, at 121.17 μmol/g. Chinese cabbage contained mostly glucocochlearin (79.88 μmol/g). These results will be useful in the development of environmentally friendly plant-based pesticides by allowing for proper control of glucosinolates based on those present in the chosen plant species.
The requirements of reliability, expeditiousness, accuracy, consistency, and simplicity for quality assessment of food products encouraged the development of non-destructive technologies to meet the ...demands of consumers to obtain superior food qualities. Hyperspectral imaging is one of the most promising techniques currently investigated for quality evaluation purposes in numerous sorts of applications. The main advantage of the hyperspectral imaging system is its aptitude to incorporate both spectroscopy and imaging techniques not only to make a direct assessment of different components simultaneously but also to locate the spatial distribution of such components in the tested products. Associated with multivariate analysis protocols, hyperspectral imaging shows a convinced attitude to be dominated in food authentication and analysis in future. The marvellous potential of the hyperspectral imaging technique as a non-destructive tool has driven the development of more sophisticated hyperspectral imaging systems in food applications. The aim of this review is to give detailed outlines about the theory and principles of hyperspectral imaging and to focus primarily on its applications in the field of quality evaluation of agro-food products as well as its future applicability in modern food industries and research.
