Showing papers in "Journal of the Science of Food and Agriculture in 2007"

Review Nutritional comparison of fresh, frozen and canned fruits and vegetables. Part 1. Vitamins C and B and phenolic compounds

Abstract: The first of a two-part review of the recent and classical literature reveals that loss of nutrients in fresh products during storage and cooking may be more substantial than commonly perceived. Depending on the commodity, freezing and canning processes may preserve nutrient value. The initial thermal treatment of processed products can cause loss of water-soluble and oxygen-labile nutrients such as vitamin C and the B vitamins. However, these nutrients are relatively stable during subsequent canned storage owing to the lack of oxygen. Frozen products lose fewer nutrients initially because of the short heating time in blanching, but they lose more nutrients during storage owing to oxidation. Phenolic compounds are also water-soluble and oxygen- labile, but changes during processing, storage and cooking appear to be highly variable by commodity. Further studies would facilitate the understanding of the changes in these phytochemicals. Changes in moisture content during storage, cooking and processing can misrepresent changes in nutrient content. These findings indicate that exclusive recommendations of fresh produce ignore the nutrient benefits of canned and frozen products. Nutritional comparison would be facilitated if future research would express nutrient data on a dry weight basis to account for changes in moisture.  2007 Society of Chemical Industry

The linkage between cell wall metabolism and fruit softening: looking to the future

Abstract: The softening that accompanies ripening of commercially important fruits exacerbates damage incurred during shipping and handling and increases pathogen susceptibility. Thus, postharvest biologists have studied fruit softening to identify ways to manage ripening and optimise fruit quality. Studies, generally based on the premise that cell wall polysaccharide breakdown causes ripening-associated softening, have not provided the insights needed to genetically engineer, or selectively breed for, fruits whose softening can be adequately controlled. Herein it is argued that a more holistic view of fruit softening is required. Polysaccharide metabolism is undoubtedly important, but understanding this requires a full appreciation of wall structure and how wall components interact to provide strength. Consideration must be given to wall assembly as well as to wall disassembly. Furthermore, the apoplast must be considered as a developmentally and biochemically distinct, dynamic 'compartment', not just the location of the cell wall structural matrix. New analytical approaches for enhancing the ability to understand wall structure and metabolism are discussed. Fruit cells regulate their turgor pressure as well as cell wall integrity as they ripen, and it is proposed that future studies of fruit softening should include attempts to understand the bases of cell- and tissue-level turgor regulation if the goal of optimising softening control is to be reached. Finally, recent studies show that cell wall breakdown provides sugar substrates that fuel other important cellular pathways and processes. These connections must be explored so that optimisation of softening does not lead to decreases in other aspects of fruit quality. ! 2007 Society of Chemical Industry

Quality of plant products from organic agriculture

Abstract: During the last decade, consumers' trust in food quality has decreased drastically, mainly because of growing ecological awareness and several food scandals (e.g. BSE, dioxins, bacterial contamination). It has been found that intensive conventional agriculture can introduce contaminants into the food chain. Consumers have started to look for safer and better controlled foods produced in more environmentally friendly, authentic and local systems. Organically produced foods are widely believed to satisfy the above demands, leading to lower environmental impacts and higher nutritive values. So far, studies have partly confirmed this opinion. Organic crops contain fewer nitrates, nitrites and pesticide residues but, as a rule, more dry matter, vitamin C, phenolic compounds, essential amino acids and total sugars than conventional crops. Organic crops also contain statistically more mineral compounds and usually have better sensory and long-term storage qualities. However, there are also some negatives: plants cultivated in organic systems generally have 20% lower yields than conventionally produced crops. Several important problems need to be addressed in the coming years: environmental, bacterial and fungal contamination of organic crops and, the most essential issue, the impact of organic food consumption on animal and human health. Copyright © 2007 Society of Chemical Industry

Sunflower proteins: overview of their physicochemical, structural and functional properties

Abstract: There is increasing worldwide demand for proteins of both animal and plant origin However, animal proteins are expensive in terms of both market price and environmental impact Among alternative plant proteins, sunflower seeds are particularly interesting in view of their widespread availability in areas where soy is not or only sparsely produced Compared with other sources of vegetable proteins, sunflower seeds have been reported to have a low content of antinutritional factors Although the absence of these factors is important, the functionality of the protein preparations will mainly determine their applicability This review provides detailed information about sunflower seed composition and processing, including processes to remove phenolic compounds from meals The main part of the review concerns the structure and functionality of the two major protein fractions, helianthinin and 2S albumins Regarding functionality, emphasis is on solubility, thermal behaviour and surface activity Protein structure and functionality are discussed as a function of extrinsic factors such as pH, ionic strength, temperature and the presence of other seed components, particularly chlorogenic acid In addition, sunflower proteins are compared from a structural and functional point of view with other plant proteins, particularly soy proteins

Nutritional comparison of fresh, frozen, and canned fruits and vegetables II. Vitamin A and carotenoids, vitamin E, minerals and fiber

Abstract: In this second part of our review, we examine the literature for changes in carotenoids, vitamin E, minerals, and fiber due to processing, storage, and cooking of fresh, frozen, and canned fruits and vegetables. While inconsistencies in methodology and reporting methods complicate interpretation of the data, the results show that these nutrients are generally similar in comparable fresh and processed products. The higher levels of carotenoids typically found in canned as compared to fresh products may be attributed to either reporting results on a wet rather than dry weight basis, greater extractability, or differences in cultivars. There are relatively few studies on processing, storage, and cooking effects on vitamin E in fruits and vegetables. Further research is needed to understand nutritional changes in those few fruits and vegetables rich in vitamin E, such as tomatoes. Minerals and fiber are generally stable to processing, storage, and cooking, but may be lost in peeling and other removal steps during processing. Mineral uptake (e.g., calcium) or addition (e.g., sodium) during processing can change the natural mineral composition of a product. Sodium concerns in canned food can be addressed by choosing products with no salt added. Since nutrient content varies considerably by commodity, cultivar, and postharvest treatments, inclusion of a wide variety of fruits and vegetables in the diet is encouraged.  2007 Society of Chemical Industry

Anthocyanins and other polyphenolics in American elderberry (Sambucus canadensis) and European elderberry (S. nigra) cultivars

Abstract: BACKGROUND: Ten genotypes representing two elderberry species, Sambucus canadensis L. (eight genotypes) and S. nigra L. (two genotypes), were examined for their anthocyanins (ACY), total phenolics (TP), ! Brix, titratable acidity (TA), and pH over two growing seasons. RESULTS: Overall, fruit generally had higher ACY, TP, ACY/TP, ! Brix, and pH in 2005 than 2004. All samples of S. canadensis had similar anthocyanin profiles to one another, but were distinctly different from S. nigra. Both species had cyanidin-based anthocyanins as major pigments. Previously unreported anthocyanins were identified in some samples in this study. Trace levels of delphinidin 3-rutinoside were present in all elderberry samples except cv. ‘Korsor’. Also, petunidin 3-rutinoside was detected in cvs ‘Adams 2’, ‘Johns’, ‘Scotia’, ‘York’, and ‘Netzer’ (S. canadensis). The identified polyphenolics of both species were mainly composed of cinnamic acids and flavonol glycosides. The major polyphenolic compounds present in S. canadensis were neochlorogenic acid, chlorogenic acid, rutin, and isorhamnetin 3-rutinoside, while chlorogenic acid and rutin were found to be major polyphenolic compounds in S. nigra. CONCLUSION: Sufficient variability was seen among these genotypes to suggest that a successful breeding program could be carried out to improve levels of the various compounds evaluated in this study. ! 2007 Society of Chemical Industry

Infusions of Portuguese medicinal plants: Dependence of final antioxidant capacity and phenol content on extraction features.

Abstract: BACKGROUND: Aqueous extracts of most medicinal plants traditionally employed in Portugal (at the ratio of 1 g plant: 110 mL water) have been assayed for total antioxidant capacity and phenol content, in order to elucidate their claimed medicinal features RESULTS: The antioxidant activity was assessed by the ABTS•+ method; the ascorbic acid equivalent values ranged from 14280 ± 01261 g L−1 for avocado (Persea americana (Lauraceae)) obtained by infusion of powder, down to 00027 ± 00012 g L−1 for olive (Olea europaea (Oleaceae)) obtained by infusion of leaves Total phenol content was determined by the Folin–Ciocalteu procedure; the gallic acid equivalent values ranged from 05541 ± 00289 g L−1 for avocado obtained by infusion of powder, down to 00053 ± 00014 g L−1 for olive obtained by boiling leaves A good correlation between total antioxidant capacity and total phenol content was found CONCLUSION: The method of powder infusion should be chosen if high concentration of antioxidants are sought On the other hand, a high antioxidant capacity and a high phenol content correlate well with the empirically established (and widely publicised) capacity to treat respiratory infections Copyright © 2007 Society of Chemical Industry

Wheat quality in organic and conventional farming: results of a 21 year field experiment

Abstract: Consumers have become more aware of healthy and safe food produced with low environmental impact. Organic agriculture is of particular interest in this respect, as manifested by 5.768 million hectares managed pursuant to Council Regulation (EEC) 2092/91 in Europe. However, there can be a considerable risk that the avoidance of chemical inputs in organic farming will result in poor food quality. Here the results of a study on the quality of wheat (Triticum aestivum L.) grown in a 21 year agrosystem comparison between organic and conventional farming in central Europe are reported. Wheat was grown in a ley (grass/clover) rotation. The 71% lower addition of plant-available nitrogen and the reduced input of other means of production to the organic field plots led to 14% lower wheat yields. However, nutritional value (protein content, amino acid composition and mineral and trace element contents) and baking quality were not affected by the farming systems. Despite exclusion of fungicides from the organic production systems, the quantities of mycotoxins detected in wheat grains were low in all systems and did not differ. In food preference tests, as an integrative method, rats significantly preferred organically over conventionally produced wheat. The findings indicate that high wheat quality in organic farming is achievable by lower inputs, thereby safeguarding natural resources.

Role of Rodents in transmission of Salmonella and Campylobacter

Abstract: Salmonella and Campylobacter are generally regarded as the most important food-borne pathogens in the world. Reduction or elimination of these pathogens in the first part of the food chain (on the farm) is important to prevent disease among consumers of animal products. In organic farming, elimination becomes more difficult, as food animals are allowed outdoors and have easy access to potential sources of hazardous pathogens. Whilst rodents are often associated by organic farmers with infrastructural damage and eating or spoiling of stored feed and products, their zoonotic risks are frequently underestimated. They can amplify the number of pathogens in the environment and transfer them to food animals. Thus organic farmers should be aware of the need for rodent control from a food safety perspective. Preferably, rodent control should form an integral part of a total package of hygiene measures to prevent transfer of food-borne pathogens. These should also include e.g. control of wild birds and flies and obligatory disinfection of boots/clothes and equipment for farm workers and visitors.

Study on the effects of laminarin, a polysaccharide from seaweed, on gut characteristics

Abstract: This study investigates whether laminarin (β1-3,β1-6-glucan), a polysaccharide from seaweed, exhibits beneficial properties for human health by analysing its effects on intestinal parameters. Anaerobic batch culture fermenters were used for the screening of the in vitro utilization of laminarin by the human gut microflora through the monitoring of biochemical and microbiological parameters. Additionally, the influence of laminarin ingestion on the composition of intestinal mucus (neutral mucins, sialomucins and sulphomucins) was studied in rats. Laminarin was almost totally (more than 90% used) fermented after 24 h of incubation with human intestinal bacteria. It was not selectively used by bifidobacteria and lactobacilli, but increased the production of propionate and butyrate. Variations of mucus composition were observed in jejunum, ileum, caecum and colon, both in lumen content and in intestinal wall, of rats after ingestion of this polysaccharide. Due to its effects on mucus composition, laminarin could influence the adherence and the translocation of bacteria across the epithelial wall. In conclusion, laminarin seems to be a modulator of the intestinal metabolism by its effects on mucus composition, intestinal pH and short chain fatty acid (SCFA) production, especially butyrate.

Comparative study of polyphenolic content and antiradical activity of cloudy and clear apple juices

Abstract: Clear and cloudy apple juices from Idared and Champion varieties were studied for their radical-scavenging effects. The polyphenolic content and composition of the juices before and after thiolysis were determined by high-performance liquid chromatography with diode array detection. Cloudy juices, especially that prepared from Champion variety, had a higher content of procyanidins than clear juices. Radical-scavenging activity was measured by electron paramagnetic resonance (EPR) spectroscopy using the stable 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical. All juices showed long-lasting radical-scavenging activity, and EPR spectra were recorded over time to follow the reaction kinetics. Scavenging of DPPH showed pseudo-first-order kinetics, which might be expected in the presence of polymerised antioxidants that prevent closer contact between the DPPH radical and hydroxyl groups. The content of polymeric procyanidins showed a linear dependence on the rate constant, suggesting that these compounds are mainly responsible for time-extended radical-scavenging activity. The antioxidant properties of apple juices were much better reproduced by EPR spectroscopy than by UV–visible measurements. The former method is especially sensitive to the concentration of polymerised or bound procyanidins, whilst the latter method requires transparent (clear) samples. Apple juices, especially cloudy ones, are a rich source of natural antioxidants that may be used in the pharmaceutical or food industry. Copyright © 2006 Society of Chemical Industry

Covalent interactions between proteins and oxidation products of caffeoylquinic acid (chlorogenic acid)

Abstract: BACKGROUND: The interactions between phenolic compounds and proteins can modify protein properties important in the food industry. To understand the effects of these interactions, the covalent interactions between caffeoylquinic acid (chlorogenic acid, CQA) oxidised by polyphenol oxidase (PPO) at acidic pH 6 (pH 6) and -lactalbumin, lysozyme and bovine serum albumin (BSA) were compared with non-enzymatically induced covalent interactions at alkaline pH (pH 9). The effects of these modifications on protein properties were examined. RESULTS: Both ways of modification seemed to result in protein modification mainly via dimeric rather than monomeric CQA quinones. These modifications led to a decrease in the number of free primary amino groups of the proteins. Modification with CQA alone induced a low degree of protein dimerisation, which also occurred through the action of PPO alone. Modification drastically reduced the solubility of lysozyme over a broad pH range, whereas that of -lactalbumin was strongly reduced only at pH values close to its pI. The solubility of BSA was much less affected than that of the other proteins and only at acidic pH. CONCLUSION: These results indicate some similarities between modifications at pH 6 and 9 and that both modifications clearly change the functional properties of globular proteins.

Chemical composition and in vitro antioxidant studies on Syzygium cumini fruit

Abstract: Syzygium cumini, widely known as Jamun, is a tropical tree that yields purple ovoid fleshy fruit. Its seed has traditionally been used in India for the treatment of diabetes. Based on the available ethno-pharmacological knowledge, further studies were extended to understand the chemical composition and antioxidant activities of three anatomically distinct parts of fruit: the pulp, kernel and seed coat. Fruit parts, their corresponding ethanol extracts and residues were evaluated for chemical composition. The alcoholic extract was evaluated for its antioxidant potential against DPPH(•), OH(•), O(2) (•-) and lipid peroxidation. The whole fruit consisted of 666.0 ± 111.0 g kg(-1) pulp, 290.0 ± 40.0 g kg(-1) kernel and 50.0 ± 15.0 g kg(-1) seed coat. Fresh pulp was rich in carbohydrates, protein and minerals. Total fatty matter was not significant in all three parts of fruit. Detailed mineral analysis showed calcium was abundant in all fruit parts and extracts. Total phenolics, anthocyanins and flavonoid contents of pulp were 3.9 ± 0.5, 1.34 ± 0.2 and 0.07 ± 0.04 g kg(-1), respectively. Kernel and seed coat contained 9.0 ± 0.7 and 8.1 ± 0.8 g kg(-1) total phenolics respectively. Jamun pulp ethanol extract (PEE), kernel ethanol extract (KEE) and seed coat ethanol extract (SCEE) showed a high degree of phenolic enrichment. DPPH radical scavenging activity of the samples and standards in descending order was: gallic acid > quercetin > Trolox > KEE > BHT > SCEE > PEE. Superoxide radical scavenging activity (IC(50)) of KEE was six times higher (85.0 ± 5.0 µg mL(-1)) compared to Trolox (540.0 ± 5.0 µg mL(-1)) and three times compared to catechin (296.0 ± 11.0 µg mL(-1)). Hydroxyl radical scavenging activity (IC(50)) of KEE was 151.0 ± 5.0 µg mL(-1) which was comparable with catechin (188.0 ± 6.0 µg mL(-1)). Inhibition of lipid peroxidation of the extracts was also studied and their activity against peroxide radicals were lower than that of standard compounds (BHT, 79.0 ± 4.0 µg mL(-1); quercetin, 166.0 ± 13.0 µg mL(-1); Trolox, 175.0 ± 4.0 µg mL(-1); PEE, 342.0 ± 17.0 µg mL(-1); KEE, 202.0 ± 13.0 µg mL(-1) and SCEE, 268.0 ± 13.0 µg mL(-1). Copyright © 2007 Society of Chemical Industry.

Flavonoid and chlorogenic acid profiles of English cider apples

Abstract: The phenolics in 20 apple cultivars comprising 19 English cider apple varieties and one dessert apple variety were analysed by high-performance liquid chromatography/tandem mass spectrometry. The cider varieties contained higher levels than the dessert apple and the peel was richer in phenolics than the flesh. The phenolic concentrations ranged between 230 and 4920 mg kg−1 fresh weight in the flesh and between 546 and 6306 mg kg−1 fresh weight in the peel. Fifteen compounds from five different phenolic groups, flavan-3-ols, flavonols, anthocyanins, hydroxycinnamates and dihydrochalcones, were detected. The major components in the flesh were 5-O-caffeoylquinic acid, procyanidin B2 and (−)-epicatechin, while (−)-epicatechin and quercetin glycosides predominated in the peel. Copyright © 2007 Society of Chemical Industry

Antioxidant capacity of Spanish honeys and its correlation with polyphenol content and other physicochemical properties

Abstract: Thirty-six Spanish honeys of different floral origins (nectars and honeydews) were assessed to estimate their radical-scavenging capacity against the stable free radical DPPH (1,1-diphenyl-2-picrylhydrazyl), their ability to inhibit enzymatic browning in apple homogenate and their clarifying effect on apple juice. These capacities were evaluated spectrophotometrically. Physicochemical parameters such as pH, acidity, net absorbance, electrical conductivity and total polyphenol content of the samples were also evaluated. It was observed that all these parameters presented a strong correlation with radical-scavenging capacity, whereas antibrowning capacity had a low correlation with conductivity and no correlation with honey pH. When data of nectar and honeydew honeys were evaluated separately, net absorbance and honey acidity seemed to be good parameters to evaluate the antioxidant activity of nectar honeys; however, in honeydew honeys there were only relationships between radical-scavenging activity and honey conductivity and between browning inhibition of homogenates and total acidity. In general, honeydew honeys showed higher antioxidant capacities than nectar honeys. Copyright © 2007 Society of Chemical Industry

Impact of enzymatic treatment on chemical composition, physicochemical properties and radical scavenging activity of goldenberry (Physalis peruviana L.) juice

Abstract: Tropical pulpy juices play an important role in nutrition as an excellent base for low-calorie and dietetic products. Goldenberry (Physalis peruviana L.) is one of the most promising exotic fruits and many interesting functional products could be developed from these berries. In this work we are reporting, for the first time, on the chemical composition and some physicochemical parameters of the goldenberry fruit juice. We have also investigated how some of these properties are affected by enzymatic treatment and pasteurisation. By enzymation, not only is the yield of juice increased, but also the macro- and micro-components. Application of enzymes, moreover, leads to juices with higher pulp content, higher acidity and higher total soluble solids. On the other side, enzyme-treated juices were characterised by lower alcohol-soluble solids and pH values. Water- and fat-soluble bioactives were estimated in appreciable amounts in the juice. The antioxidative potential of different processed juices was assessed by means of bleaching of the stable 1,1-diphenyl-2-picrylhydrazyl radicals and the resulting values were correlated with each of the antioxidant compounds. The results obtained can be considered very satisfactory and the juice could be widely appreciated when compared with other products commonly available on the market. The data are helpful for the optimisation of goldenberry juice production. It was the purpose to present a comprehensive assessment of the goldenberry juice and to address the potential for its delivery in functional drinks. Copyright © 2006 Society of Chemical Industry

Effectiveness of organic acid, ozonated water and chlorine dippings on microbial reduction and storage quality of fresh-cut iceberg lettuce

Abstract: Background The comparative effects of organic (citric and lactic) acids, ozone and chlorine on the microbiological population and quality parameters of fresh-cut lettuce during storage were evaluated. Results Dipping of lettuce in 100 mg L(-1) chlorine solution reduced the numbers of mesophilic and psychrotrophic bacteria and Enterobacteriaceae by 1.7, 2.0 and 1.6 log(10) colony-forming units (CFU) g(-1) respectively. Treatment of lettuce with citric (5 g L(-1)) and lactic (5 mL L(-1)) acid solutions and ozonated water (4 mg L(-1)) reduced the populations of mesophilic and psychrotrophic bacteria by 1.7 and 1.5 log(10) CFU g(-1) respectively. Organic acid dippings resulted in lower mesophilic and psychrotrophic counts than ozonated water and chlorine dippings during 12 days of storage. Lactic acid dipping effectively reduced (by 2.2 log(10) CFU g(-1)) and maintained low populations of Enterobacteriaceae on lettuce for the first 6 days of storage. No significant (P > 0.05) changes were observed in the texture and moisture content of lettuce samples dipped in chlorine, organic acids and ozonated water during storage. Colour, β-carotene and vitamin C values of fresh-cut iceberg lettuce did not change significantly (P > 0.05) until day 8. Conclusion Lactic and citric acid and ozonated water dippings could be alternative treatments to chlorine dipping to prolong the shelf life of fresh-cut iceberg lettuce. Copyright © 2007 Society of Chemical Industry.

Dietary oligochitosan supplementation enhances immune status of broilers

Abstract: Oligochitosan (COS) is a type of prebiotic, which favourably alters the intestinal microflora balance, inhibits the growth of harmful bacteria, promotes good digestion and boosts immune function. The effect of dietary COS supplementation on immune function in broilers was assessed by feeding graded levels (0, 50, 100, 150 mg kg−1) of COS. Two thousand four hundred male commercial Avian® broilers (1 day old) were assigned randomly to five dietary treatment groups (60 birds/pen with eight pens per treatment). Diet A was a typical maize- and soybean meal-based diet supplemented with 6 mg kg−1 antibiotics of flavomycin (positive control). Diet B was the basal diet without any supplement. Diets C, D and E were formulated by addition of 50, 100, 150 mg kg−1 of COS to the basal diet, respectively. On the morning of days 21 and 42, a total of 64 (eight birds/pen with eight pens per treatment) of the growth experimental birds were killed by cervical dislocation, respectively for determination of serum concentrations of IgG, IgA and IgM, and weights of spleen, bursa and thymus. Compared with broilers fed the control and the positive control diets, dietary supplementation with COS increased (P < 0.001) serum concentrations of IgG, IgA, and IgM, with the greatest response for the 100 mg kg−1COS supplementation. Chitosan oligosaccharides supplementation also enhanced the immune organ development. Results suggest COS can improve immune response in birds. Through positive modulation of the immune response, COS has great potential as an effective, antibiotic-like growth promoter for poultry. Copyright © 2006 Society of Chemical Industry

Evaluation of antioxidant capacity of some fruit and vegetable foods: efficiency of extraction of a sequence of solvents

Abstract: All methods for assessing the total antioxidant capacity (TAC) of food samples are strongly affected by the solvents used during extraction. In recent years a sequential solvent extraction procedure utilising water and acetone has been widely used for TAC measurements of foods. To better understand the efficiency of this procedure in terms of the amount of extracted antioxidants and the subsequent measurement of TAC, two vegetables (onion and spinach) and two fruits (orange and tomato) were sequentially extracted with water, acetone and chloroform. Each extract fraction was analysed separately for its content of known antioxidant compounds by specific procedures and for its TAC by the Trolox equivalent antioxidant capacity assay. The results showed that the compounds in the water and acetone extracts were the main contributors to TAC. The chloroform extracts did not contribute to TAC, with the exception of the spinach extract, owing to the presence of low levels of carotenoids. In conclusion, the analysed extraction procedure was more effective for foods rich in water-soluble antioxidants than for those rich in lipid-soluble antioxidants.

The potential use of hydrolysed konjac glucomannan as a prebiotic

Abstract: Konjac glucomannan hydrolysate was derived enzymatically from konjac flour under optimal conditions. A number of culture strains of lactobacilli and bifidobacteria were grown on De Man, Rogosa and Sharpe (MRS) media supplemented with the hydrolysate. This hydrolysate stimulated the growth of all strains examined. Colony sizes of those strains grown on konjac hydrolysate were significantly (P = 0.001) bigger than those grown on pectin or xylan hydrolysates. Bacterial growth profiles were also conducted on nutrient agar (MRS or modified MRS agar containing konjac hydrolysate) using single strains of lactobacilli or bifidobacteria (Lactobacillus acidophilus, Lactobacillus casei or Bifidobacterium adolescentis), single pathogen cultures (Escherichia coli or Listeria monocytogenes) or mixed bacterial cultures (from chicken breast extract). Although the growth of lactobacilli inhibited the growth of pathogens (single or mixed culture) the pathogens could not grow on the konjac hydrolysate as a sole carbon source. Microbial growth profiles using konjac hydrolysate or inulin in UHT milk were also investigated. The results showed that the numbers of colony forming units (cfu) obtained from milk containing the konjac hydrolysate were significantly (P = 0.01) higher than those containing inulin. It is suggested that the unique properties of konjac hydrolysate make it universally valuable as a prebiotic which can be applied to a wide range of foods, feeds and healthcare/pharmaceutical products.

The coming of age of agroforestry

Abstract: The success of modern agricultural and forestry production can be largely attributed to monoculture systems using a few select species. In the drive for maximizing yield and profit, the age-old tradition of using combined farming systems was essentially avoided and in some cases this has resulted in environmental problems such as land and water degradation and increased land clearing. During the last 30 years, however, the positive benefits of agroforestry to the producer and the environment have been increasingly recognized. Combining trees and crops in spatial or temporal arrangements has been shown to improve food and nutritional security and mitigate environmental degradation, offering a sustainable alternative to monoculture production. By providing supportive and complimentary roles with a flexible approach, agroforestry can offer specific social and environmental benefits across a range of landscapes and economies. More research and effort is needed to explore the full potential of agroforestry applications and to fuel awareness. As the plethora of benefits of agroforestry are realized, modern land-use systems are evolving towards a more sustainable and holistic approach to land management. Copyright © 2007 Society of Chemical Industry

High hydrostatic pressure treatment and storage of carrot and tomato juices: Antioxidant activity and microbial safety

Abstract: The application of high hydrostatic pressure (HHP) (250MPa, 35 ◦ C for 15min) and thermal treatment (80 ◦ C for 1min) reduced the microbial load of carrot and tomato juices to undetectable levels. Different combinations of HHP did not cause a significant change in the ascorbic acid content of either juice (P > 0.05). Both heat treatments (60 ◦ C for 5-15min and 80 ◦ C for 1min) resulted in a significant loss (P < 0.05) in the free-radical scavenging activity as compared to untreated samples. HHP-treated juices showed a small loss of antioxidants (below 10%) during storage. The ascorbic acid content of pressurized tomato and carrot juices remained over 70 and 45% after 30days of storage, respectively. However, heat treatment caused a rapid decrease to 16-20%. Colour changes were minor (� E = 10) for pressurised juices but for heat-pasteurised samples it was more intense and higher as a result of insufficient antioxidant activity. HHP treatment (250MPa, 35 ◦ C for 15min) led to a better product with regard to anti-radical scavenging capacity, ascorbic acid content and sensory properties (colour, pH) of the tomato and carrot juices compared to conventional pasteurisation. Therefore, HHP can be recommended not only for industrial production but also for safe storage of fresh juices, such as tomato and carrot, even at elevated storage temperatures (25 ◦ C).  2007 Society of Chemical Industry

Medicinal plant species with potential antidiabetic properties.

Abstract: Diabetes mellitus is one of the world's major diseases. It currently affects an estimated 143 million people worldwide and the number is growing rapidly. In the USA alone, about 20.8 million or 7% of the population suffer from diabetes or related complications. The estimated direct and indirect costs of diabetes exceed US$ 132 billion annually. Plant-based medicinal products have been known since ancient times, and several medicinal plants and their products (active natural principles and crude extracts) have been used to control diabetes in the traditional medicinal systems of many cultures worldwide, including those of the Asian Indians, Chinese and South Americans. A limited number of these plant species have been studied and validated for their hypoglycaemic properties using diabetic animal models and in clinical studies using human subjects. Several oral hypoglycaemic agents are the primary forms of treatment for diabetes. However, prominent side-effects of such drugs are the main reason for an increasing number of people seeking alternative therapies that may have less severe or no side-effects. Thus plant-based herbal drugs or botanicals are emerging as the primary components of holistic approaches to diabetes management. In this review, selected species that have been validated for their hypoglycaemic or antihyperglycaemic properties using laboratory diabetic animal models and in clinical trials using human subjects, and reported in refereed journals are presented. Copyright © 2007 Society of Chemical Industry

Effect of flaxseed and wheat flour blends on dough rheology and bread quality

Abstract: The rheological and baking properties of flaxseed/wheat composite flours were studied. Flaxseed flour was used to replace 50, 100, 150 and 200 g kg−1 of wheat flour in bread. Farinographic studies showed that water absorption, dough development time and mixing tolerance index increased as the amount of flaxseed flour increased, while dough stability decreased at 100, 150 and 200 g kg−1 of flaxseed flour substitution. The extensographic energy of dough also decreased at 150 and 200 g kg−1 flaxseed levels. The addition of increasing amounts of flaxseed flour caused a decrease in extensibility. Doughs containing 100, 150 and 200 g kg−1 flaxseed flour showed resistance to extension comparable to that of control dough. The specific volume of flaxseed flour breads was similar to that of control bread. Crust L, a, b values of breads with flaxseed flour were lower than those of control bread. Breads with flaxseed flour gave lower crumb L and b values and higher a values than control bread. The sensory properties showed that an acceptable bread could be produced using flaxseed flour up to a level of 200 g kg−1. Copyright © 2007 Society of Chemical Industry

Influence of postharvest UV-C treatment on refrigerated storage of minimally processed broccoli (Brassica oleracea var.Italica)

Abstract: Fil: Lemoine, Maria Laura. Provincia de Buenos Aires. Gobernacion. Comision de Investigaciones Cientificas. Centro de Investigacion y Desarrollo en Criotecnologia de Alimentos. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Centro Cientifico Tecnologico Conicet - La Plata. Centro de Investigacion y Desarrollo en Criotecnologia de Alimentos. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Centro de Investigacion y Desarrollo en Criotecnologia de Alimentos; Argentina

Retention of carotenoids in cassava roots submitted to different processing methods

Abstract: Large genetic variation in carotenoid content has been reported after screening roots from thousands of cassava genotypes. Moreover, these pigments have to withstand different processing methods before cassava is consumed. True retention of -carotene from cassava roots that had been boiled, oven-dried, sun-dried, shadow-dried, or used for gari preparation was measured. True retention was also measured after storing for 2 or 4 weeks some of the products of these processing methods. Oven-drying, shadow drying and boiling retained the highest levels of -carotene (71.9, 59.2 and 55.7%, respectively) and gari the lowest (about 34.1%). Higher retention was observed when dried roots were kept as chips rather than as flour. Storage of flour packed in plastic bags under vacuum unexpectedly resulted in higher losses than storage of flour packed in plastic bags without the application of vacuum. Losses were higher during the first 2 weeks and tended to be considerably lower during the second 2 weeks of storage. Copyright © 2006 Society of Chemical Industry.

Procyanidins: extraction and micro- encapsulation

Abstract: As by-products of grape juice and wine production, grape seeds are a rich source of procyanidins but are usually discarded as waste. We have treated grape seeds with supercritical fluid extraction to remove the oils and have extracted the procyanidins from the residues. In order to extend the shelf life, micro-encapsulating methods for procyanidins were studied: the use of gum arabic and maltodextrin as wall materials (the contents of arabic gum and maltodextrin were 40% and 60%, respectively). The raw materials were then mixed (the ratio of core substance to wall material was 30:70 w/w and the content of the slurry was 20% w/v). After homogenisation, spray drying was used to prepare microcapsules. The micro-encapsulation efficiency was up to 88.84%. Analysis of the product showed that the procyanidin was not changed during the processing and the procyanidin microcapsule membrane was uninterrupted and with fairly good integrity. The stability of the products was also obviously improved. Copyright © 2007 Society of Chemical Industry

Effect of phytate and storage conditions on the development of the ‘hard‐to‐cook’ phenomenon in common beans

Abstract: Postharvest storage of beans (Phaseolus vulgaris L.) can alter the color, texture, flavor and time required for cooking. These alterations have been associated with the ‘hard-to-cook’ phenomenon (HTC) and a reduction in the quality of the grains. HTC has been linked to the genotype, environment and/or storage conditions of the grains, but very few studies have shown the interrelationship between these factors. Therefore, the objective of this study was to analyze the effect of two genotypes, Paraiso and Peruano, grown under the same phosphorus levels, on the development of HTC. These genotypes were evaluated for phytate, protein, tannin and phosphorus contents, hydration time and cooking time when stored for 45, 90 and 135 days, at 29 °C and 5 °C at a relative humidity of 75%. HTC was observed in Peruano after 135 days, which correlated with a reduction in the phytate content. Paraiso did not show HTC even though there was a reduction of tannins during the storage period. The lower storage temperature appeared to control HTC for both genotypes. Overall, the content of phytate can be an indicative factor for the cookability of fresh beans when the relationship between genotype and storage conditions has been determined. Copyright © 2007 Society of Chemical Industry

Stabilization of astaxanthin in edible oils and its use as an antioxidant

Abstract: An astaxanthin preparation from Haematococcus pluvialis comprising approx. 85% astaxanthin (predominantly esters) plus other carotenoids was examined for storage stability in different vegetable oils. The preparation was added to coconut, rice bran, groundnut, mustard, sesame (gingelly), olive or sunflower oils at 0.1% (w/w) and analysed after storage at room temp. for 4 months. Effects of heating (8 h at 70, 90, 120 or 150C) on preparation stability (expressed in terms of astaxanthin) were also determined in selected oils. Astaxanthin retained reasonable stability in oils during storage at room temp. with some variation noted in extent of carotenoid and colour loss. Sesame, rice bran and palm oils retained 90% of astaxanthin when heated at 70C prior to storage. Palm oil was able to retain 90% of astaxanthin (present in ester form) when heated at 90C; however significant carotenoid loss was noted when aqueous solutions of astaxanthin were heated at 70-90C. Heating at 120 or 150C (sesame or palm oils) resulted in 60-90% carotenoid loss without altering fatty acid composition. Antioxidative activity of carotenoids stored in oils was similar to that of BHA.

Effect of deficit irrigation on apricot fruit quality at harvest and during storage

Abstract: on, ETSIA (UPCT) Abstract: The effect of different irrigation strategies on the fruit quality at harvest and during storage at 1 ◦ Co f 'B ´ ulida' apricots (Prunus armeniaca L.) was studied. Irrigation treatments consisted of a control irrigated at 100% of crop evapotranspiration (ETc) throughout the season, and two deficit irrigation treatments consisting of continuous irrigation at 50% of control, and regulated deficit irrigation (RDI) at 100% of ETc during the critical periods (second rapid fruit growth and early post-harvest) and at 25% during the rest of the season. Fruits at harvest from both deficit irrigation treatments showed higher values of total soluble solids (TSS), titratable acidity and hue angle (h ◦ ) than control fruits, whereas their diameter, fresh weight, firmness and maturity index values were similar to those in the control. During the first 10 days of the 30-day chilling storage period, higher TSS and h ◦ values were found in deficit irrigated fruits, whilst the other parameters were similar for all treatments. Weight loss and fungal attacks (mainly Rhizopus sp. and Monilinia sp.) during a subsequent retail sale period of 4 days at 13 ◦ C were the lowest in RDI. Deficit irrigation was demonstrated to be commercially advantageous for keeping fruit quality, saving considerable amounts of water.  2007 Society of Chemical Industry