Showing papers in "Journal of the Science of Food and Agriculture in 2010"

Nutrition facts and functional potential of quinoa (Chenopodium quinoa willd.), an ancient Andean grain: a review.

Abstract: Quinoa, Chenopodium quinoa Willd., is an Amaranthacean, stress-tolerant plant cultivated along the Andes for the last 7000 years, challenging highly different environmental conditions ranging from Bolivia, up to 4.500 m of altitude, to sea level, in Chile. Its grains have higher nutritive value than traditional cereals and it is a promising worldwide cultivar for human consumption and nutrition. The quinoa has been called a pseudo-cereal for botanical reasons but also because of its unusual composition and exceptional balance between oil, protein and fat. The quinoa is an excellent example of ‘functional food’ that aims at lowering the risk of various diseases. Functional properties are given also by minerals, vitamins, fatty acids and antioxidants that can make a strong contribution to human nutrition, particularly to protect cell membranes, with proven good results in brain neuronal functions. Its minerals work as cofactors in antioxidant enzymes, adding higher value to its rich proteins. Quinoa also contains phytohormones, which offer an advantage over other plant foods for human nutrition. c � 2010 Society of Chemical Industry

Role of mineral nutrition in minimizing cadmium accumulation by plants

Abstract: Cadmium (Cd) is a highly toxic heavy metal for both plants and animals. The presence of Cd in agricultural soils is of great concern regarding its entry into the food chain. Cadmium enters into the soil-plant environment mainly through anthropogenic activities. Compounds of Cd are more soluble than other heavy metals, so it is more available and readily taken up by plants and accumulates in different edible plant parts through which it enters the food chain. A number of approaches are being used to minimize the entry of Cd into the food chain. Proper plant nutrition is one of the good strategies to alleviate the damaging effects of Cd on plants and to avoid its entry into the food chain. Plant nutrients play a very important role in developing plant tolerance to Cd toxicity and thus, low Cd accumulation in different plant parts. In this report, the role of some macronutrients (nitrogen, phosphorus, sulfur and calcium), micronutrients (zinc, iron and manganese), and silicon (a beneficial nutrient) has been discussed in detail as to how these nutrients play their role in decreasing Cd uptake and accumulation in crop plants.

Antioxidant properties, radical scavenging activity and biomolecule protection capacity of flavonoid naringenin and its glycoside naringin: a comparative study

Abstract: BACKGROUND: This study was designed to evaluate and compare antioxidant capacity and radical scavenging activity of naringin and its aglycone by different in vitro assays. The effects of flavanones on lipid peroxidation, glutathione (GSH) oxidation and DNA cleavage were also assessed. RESULTS: The results showed that naringenin exhibited higher antioxidant capacity and hydroxyl and superoxide radical scavenger efficiency than naringin. Our results evidenced that glycosylation attenuated the efficiency in inhibiting the enzyme xanthine oxidase and the aglycone could act like a more active chelator of metallic ions than the glycoside. Additionally, naringenin showed a greater effectiveness in the protection against oxidative damage to lipids in a dose-dependent manner. Both flavanones were equally effective in reducing DNA damage. However, they show no protective effect on oxidation of GSH. CONCLUSION: The data obtained support the importance of characterizing the ratio naringin/naringenin in foods when they are evaluated for their health benefits. Copyright © 2010 Society of Chemical Industry

Multi-laboratory validation of a standard method for quantifying proanthocyanidins in cranberry powders.

Abstract: BACKGROUND: The objective of this study was to validate an improved 4-dimethylaminocinnamaldehyde (DMAC) colorimetric method using a commercially available standard (procyanidin A2), for the standard method for quantification of proanthocyanidins (PACs) in cranberry powders, in order to establish dosage guidelines for the uropathogenic bacterial anti-adhesion effect of cranberry. RESULTS: Commercially available cranberry samples were obtained (five from U.S. sources and six from European sources) for PAC quantification in five different analytical laboratories. Each laboratory extracted and analyzed the samples using the improved DMAC method. Within-laboratory variation (mean ± SD) was 4.1 ± 1.7% RSD (range, 2.3–6.1% RSD) and the between laboratory variability was 16.9 ± 8.5% RSD (range, 8–32% RSD). For comparative purposes, the cranberry samples were alternatively quantified using weights of extracted PACs (gravimetric). The correlation coefficient between the two methods was 0.989. CONCLUSION: This improved DMAC method provides a simple, robust and relatively specific spectrophotometric assay for total PACs in cranberry samples using commercially available procyanidin A2 dimer as a standard. DMAC is most useful within a given type of food such as cranberries, but may not be appropriate for comparing concentrations across different food types, particularly in those cases where large differences exist among the relative amounts of each oligomer and polymer. Copyright © 2010 Society of Chemical Industry

Seasonal variation in content, chemical composition and antimicrobial and cytotoxic activities of essential oils from four Mentha species.

Abstract: BACKGROUND: The aim of the present study was to appraise variation in the chemical composition, and antimicrobial and cytotoxic activities of essential oils from the leaves of four Mentha species—M. arvensis, M. piperita, M. longifolia and M. spicata—as affected by harvesting season. Disc diffusion and broth microdilution susceptibility assays were used to evaluate the antimicrobial activity of Mentha essential oils against a panel of microorganisms. The cytotoxicity of essential oils was tested on breast cancer (MCF-7) and prostate cancer (LNCaP) cell lines using the MTT assay. RESULTS: The essential oil contents of M. arvensis, M. piperita, M. longifolia and M. spicata were 17.0, 12.2, 10.8 and 12.0 g kg−1 from the summer and 9.20, 10.5, 7.00 and 9.50 g kg−1 from the winter crops, respectively. Gas chromatographic–mass spectrometric analysis revealed that mostly quantitative rather than qualitative variation was observed in the oil composition of each species. The principal chemical constituents determined in M. arvensis, M. piperita, M. longifolia and M. spicata essential oils from both seasons were menthol, menthone, piperitenone oxide and carvone, respectively. The tested essential oils and their major components exhibited notable antimicrobial activity against most of the plant and human pathogens tested. The tested essential oils also exhibited good cytotoxicity potential. CONCLUSION: Of the Mentha essential oils tested, M. arvensis essential oil showed relatively better antimicrobial and cytotoxic activities. A significant variation in the content of most of the chemical components and biological activities of seasonally collected samples was documented. Copyright © 2010 Society of Chemical Industry

Consumers' purchase intention of organic food in China

Abstract: BACKGROUND: The global market for organic food has developed significantly in the past decade. The organic food industry in China is export oriented, with production growing rapidly, although the domestic market remains relatively small. This paper surveys 432 consumers from three cities in China, consequently establishing a logit model to analyse the main factors affecting consumers' choice for organic food. RESULTS: The result indicates that Chinese consumers' intent to purchase organic food is strongly affected by factors such as income, degree of trust in organic food, degree of acceptance of organic food price, and consumers' concern on self-health. This intent is only slightly affected by factors such as consumers' age, education level and concern about environmental protection. CONCLUSION: Based on the results, the following measures are recommended: reduce the cost of organic food through multiple channels to cut down the market price; establish and perfect the supervision system of organic food; and promote organic food through various channels. Copyright © 2010 Society of Chemical Industry

Walnut (Juglans regia L.): genetic resources, chemistry, by-products

Abstract: Walnut (Juglans regia L) is the most widespread tree nut in the world There is a great diversity of genotypes differing in forestry, productivity, physical and chemical nut traits Some of them have been evaluated as promising and may serve as germplasm sources for breeding The nutritional importance of the nut is related to the seed (kernel) It is a nutrient-dense food mainly owing to its oil content (up to 740 g kg(-1) in some commercial varieties), which can be extracted easily by screw pressing and consumed without refining Walnut oil composition is dominated largely by unsaturated fatty acids (mainly linoleic together with lesser amounts of oleic and linolenic acids) Minor components of walnut oil include tocopherols, phospholipids, sphingolipids, sterols, hydrocarbons and volatile compounds Phenolic compounds, present at high levels in the seed coat but poorly extracted with the oil, have been extensively characterised and found to possess strong antioxidant properties The oil extraction residue is rich in proteins (unusually high in arginine, glutamic and aspartic acids) and has been employed in the formulation of various functional food products This review describes current scientific knowledge concerning walnut genetic resources and composition as well as by-product obtainment and characteristics

Incorporation of Chlorella vulgaris and Spirulina maxima biomass in pasta products. Part 1: Preparation and evaluation.

Abstract: BACKGROUND: Microalgae are able to enhance the nutritional content of conventional foods and hence to positively affect human health, due to their original chemical composition. The aim of the present study was to prepare fresh spaghetti enriched with different amounts of microalgae biomass (Chlorella vulgaris and Spirulina maxima) and to compare the quality parameters (optimal cooking time, cooking losses, swelling index and water absorption), chemical composition, instrumental texture and colour of the raw and cooked pasta enriched with microalgae biomass with standard semolina spaghetti. RESULTS: The incorporation of microalgae results in an increase of quality parameters when compared to the control sample. The colour of microalgae pastas remained relatively stable after cooking. The addition of microalgae resulted in an increase in the raw pasta firmness when compared to the control sample. Of all the microalgae studied, an increase in the biomass concentration (0.5–2.0%) resulted in a general tendency of an increase in the pasta firmness. Sensory analysis revealed that microalgae pastas had higher acceptance scores by the panellists than the control pasta. CONCLUSION: Microalgae pastas presented very appellative colours, such as orange and green, similar to pastas produced with vegetables, with nutritional advantages, showing energetic values similar to commercial pastas. The use of microalgae biomass can enhance the nutritional and sensorial quality of pasta, without affecting its cooking and textural properties. Copyright © 2010 Society of Chemical Industry

Effects of lutein and zeaxanthin on aspects of eye health

Abstract: Lutein and zeaxanthin are members of the oxygenated carotenoids found particularly in egg yolks and dark-green leafy vegetables. A great deal of research has focused on their beneficial roles in eye health. The present article summarises the current literature related to the bioactivity of these carotenoids, emphasising their effects and possible mechanisms of action in relation to human eye health. Available evidence demonstrates that lutein and zeaxanthin are widely distributed in a number of body tissues and are uniquely concentrated in the retina and lens, indicating that each has a possible specific function in these two vital ocular tissues. Most of epidemiological studies and clinical trials support the notion that lutein and zeaxanthin have a potential role in the prevention and treatment of certain eye diseases such as age-related macular degeneration, cataract and retinitis pigmentosa. The biological mechanisms for the protective effects of these carotenoids may include powerful blue-light filtering activities and antioxidant properties. Although most studies point towards significant health benefits from lutein and zeaxanthin, further large-scale randomised supplementation trials are needed to define their effects on ocular function in health and disease.

Chemical composition and nutritional quality of sea cucumbers

Abstract: BACKGROUND: The dried form of sea cucumbers has been a seafood and medicinal cure for Asians over many centuries. In this study the chemical composition and nutritional quality of eight common sea cucumbers (Stichopus herrmanni, Thelenota ananas, Thelenota anax, Holothuria fuscogilva, Holothuria fuscopunctata, Actinopyga mauritiana, Actinopyga caerulea and Bohadschia argus) were determined. RESULTS: All species except T. anax and A. caerulea had higher protein and lower fat levels. A. mauritiana and B. argus had less ash content. Glycine was the dominant amino acid found in all species, and content ranged from 126 to 216 mg g(-1) of crude protein. All species exhibited low lysine : arginine ratio and higher essential amino acid scores were obtained by threonine and phenylalanine + tyrosine. A. mauritiana had proportionally less saturated fatty acids (31.23%), and more monounsaturated fatty acids (45.64%) and polyunsaturated fatty acids (PUFA, 23.13%) than other species. Arachidonic acid (C20 : 4n-6) was the major PUFA in all species. T. ananas, A. mauritiana and A. caerulea contained more n-3 PUFA. The n-3/n-6 ratios of eight sea cucumbers species ranged from 0.25 to 0.61. CONCLUSION: Sea cucumbers are a seafood with high protein and low fat levels. The amino acid contents were similar but fatty acid profiles were different among species. The comparison showed that T. ananas, A. mauritiana and B. argus possessed higher nutritional values than other sea cucumber species. (c) 2010 Society of Chemical Industry

Antioxidant properties of various solvent extracts of potato peel, sugar beet pulp and sesame cake

Abstract: BACKGROUND: Growing interest in the replacement of synthetic food antioxidants by natural ones has fostered research on vegetable sources and screening of raw materials to identify new antioxidants. The food-processing industry generates substantial quantities of phenolic-rich by-products that could be valuable natural sources of antioxidants. In this study the antioxidant properties and total phenolic, flavonoid and flavonol contents of three industrial by-products, sugar beet pulp, sesame cake and potato peel, extracted with various solvents were examined. Since different antioxidant compounds have different mechanisms of action, several methods were used to assess the antioxidant efficacy of extracts. RESULTS: Among the six solvents tested, methanol gave the highest extract yield of potato peel and sugar beet pulp, while diethyl ether gave the highest extract yield of sesame cake. Methanol exhibited the highest extraction ability for phenolic compounds, with total phenolics amounting to 2.91, 1.79 and 0.81 mg gallic acid equivalent g−1 dry weight in potato peel, sugar beet pulp and sesame cake extracts respectively, and also showed the strongest antioxidant capacity in the three assays used. All three methods proved that potato peel extract had the highest antioxidant activity owing to its high content of phenolic compounds and flavonoids. CONCLUSION: On the basis of the results obtained, potato peel, sugar beet pulp and sesame cake extracts could serve as natural antioxidants owing to their significant antioxidant activity. Therefore they could be used as preservative ingredients in the food and/or pharmaceutical industries. Copyright © 2009 Society of Chemical Industry

Composition of European chestnut (Castanea sativa Mill.) and association with health effects: fresh and processed products

Abstract: Chestnut fruits are highly regarded and widely consumed throughout Europe, America and Asia. Various commercial forms are available, e.g. fresh and industrially processed. There have been various reviews on the composition of chestnut fruits but there has not been a comprehensive review of the different health benefits that this fruit can provide. This review is focused on the composition and associated health effects of European fresh chestnut (Castanea sativa Mill.) fruits and their home-processed and industrial products, e.g. boiled, roasted, frozen, and 'marron glacees'. We also expand the knowledge of chestnut uses by presenting data for other chestnut materials that have potential applications as new foods, as sources of antioxidants, and as sources of other useful bioactives. There is considerable literature data on nutrients in fresh chestnut fruits but less information on bioactive non-nutrients such as phenolics. Chestnuts are mostly consumed as processed forms, and the different types of processing clearly affect the nutrient and non-nutrient composition of the fruits. The benefits that this fruit can provide for human and animal health are numerous, but it is clear that improvements can be made for both production and quality of chestnut products, e.g. genetic selection and optimizing industrial processing.

Phenolic and carotenoid profiles of papaya fruit (Carica papaya L.) and their contents under low temperature storage

Abstract: BACKGROUND: Tropical fruits are rich in phenolic and carotenoid compounds, and these are associated with cultivar, pre- and postharvest handling factors. The aim of this work was to identify major phenolics and carotenoids in ‘Maradol’ papaya fruit and to investigate their response to storage temperature. RESULTS: Ferulic acid, caffeic acid and rutin were identified in ‘Maradol’ papaya fruit exocarp as the most abundant phenolic compounds, and lycopene, β-cryptoxanthin and β-carotene were identified in mesocarp as the major carotenoids. Ranges of contents of ferulic acid (1.33‐1.62 g kg −1 dry weight), caffeic acid (0.46‐0.68 g kg −1 dw) and rutin (0.10‐0.16 g kg −1 dw) were found in papaya fruit, which tend to decrease during ripening at 25 ◦ C. Lycopene (0.0015 to 0.012 g kg −1 fresh weight) and β-cryptoxanthin (0.0031 to 0.0080 g kg −1 fw) were found in fruits stored at 25 ◦ C, which tend to increase during ripening. No significant differences in β-carotene or rutin contents were observed in relation to storage temperature. CONCLUSION: Phenolics and carotenoids of ‘Maradol’ papaya were influenced by postharvest storage temperature with exception of β-carotene and rutin. Ripe papaya stored at 25 ◦ C had more carotenoids than those stored at 1 ◦ C. Low (chilling) temperature (1 ◦ C) negatively affected the content of major carotenoids, except β-carotene, but preserved or increased ferulic and caffeic acids levels, as compared to high (safe) temperature (25 ◦ C). c � 2010 Society of Chemical Industry

Recent advances in extending the shelf life of fresh Agaricus mushrooms: a review.

Abstract: Postharvest browning of Agaricus mushrooms is a severe problem that reduces the shelf life of harvested mushrooms because of their continued respiration and biochemical activity. There are no simple answers and no single treatment is known to limit overall quality deterioration. However, there are several strategies that are being implemented in order to reduce the rate of respiration for mushrooms. Packaging technology is the common denominator that allows us to implement these strategies and thus is key to quality preservation. In this review, first, the major factors involved in postharvest quality deterioration are discussed and then technological advances/methods used to counteract these hurdles are presented.

Utilisation of corn (Zea mays) bran and corn fiber in the production of food components.

Abstract: The milling of corn for the production of food constituents results in a number of low-value co-products. Two of the major co-products produced by this operation are corn bran and corn fiber, which currently have low commercial value. This review focuses on current and prospective research surrounding the utilization of corn fiber and corn bran in the production of potentially higher-value food components. Corn bran and corn fiber contain potentially useful components that may be harvested through physical, chemical or enzymatic means for the production of food ingredients or additives, including corn fiber oil, corn fiber gum, cellulosic fiber gels, xylo-oligosaccharides and ferulic acid. Components of corn bran and corn fiber may also be converted to food chemicals such as vanillin and xylitol. Commercialization of processes for the isolation or production of food products from corn bran or corn fiber has been met with numerous technical challenges, therefore further research that improves the production of these components from corn bran or corn fiber is needed.

Effect of prebiotics on viability and growth characteristics of probiotics in soymilk.

Abstract: BACKGROUND: Soy products have attracted much attention lately as carriers for probiotics. This study was aimed at enhancing the growth of probiotics in soymilk via supplementation with prebiotics. RESULTS:Lactobacillus sp. FTDC 2113, Lactobacillus acidophilus FTDC 8033, Lactobacillus acidophilus ATCC 4356, Lactobacillus casei ATCC 393, Bifidobacterium FTDC 8943 and Bifidobacterium longum FTDC 8643 were evaluated for their viability and growth characteristics in prebiotic-supplemented soymilk. In the presence of fructooligosaccharides (FOS), inulin, mannitol, maltodextrin and pectin, all strains showed viability exceeding 7 log10 colony-forming units mL−1 after 24 h. Their growth was significantly (P < 0.05) increased on supplementation with maltodextrin, pectin, mannitol and FOS. Additionally, supplementation with FOS, mannitol and maltodextrin increased (P < 0.05) the production of lactic acid. Supplementation with FOS and maltodextrin also increased the α-galactosidase activity of probiotics, leading to enhanced hydrolysis and utilisation of soy oligosaccharides. Finally, prebiotic supplementation enhanced the utilisation of simpler sugars such as fructose and glucose in soymilk. CONCLUSION: Supplementation with prebiotics enhances the potential of soymilk as a carrier for probiotics. Copyright © 2009 Society of Chemical Industry

Carotenoid content impacts flavor acceptability in tomato (Solanum lycopersicum).

Abstract: BACKGROUND: Tomatoes contain high levels of several carotenoids including lycopene and β-carotene. Beyond their functions as colorants and nutrients, carotenoids are precursors for important volatile flavor compounds. In order to assess the importance of apocarotenoid volatiles in flavor perception and acceptability, we conducted sensory evaluations of near-isogenic carotenoid biosynthetic mutants and their parent, Ailsa Craig. RESULTS: The carotenoid contents of these tomatoes were extremely low in the r mutant, increased in lycopene in old gold, and higher in tetra-cis-lycopene and ζ-carotene in tangerine. The volatiles derived from these carotenoids (β-ionone, geranylacetone and 6-methyl-5-hepten-2-one) were proportionally altered relative to their precursors. Fruits were also analyzed for soluble solids, sugars, acids and flavor volatiles. Consumer panels rated the r mutant lowest for all sensory attributes, while Ailsa Craig was generally rated highest. Old gold and tangerine were rated intermediate in two of the three harvests. CONCLUSIONS: Several chemicals were negatively correlated with at least one of the hedonic scores while several others were positively correlated with tomato flavor acceptability. The results permitted identification of positive and negative interactions of volatiles with tomato flavor. Copyright © 2010 Society of Chemical Industry

Impact of ultrafiltration and nanofiltration of an industrial fish protein hydrolysate on its bioactive properties

Abstract: BACKGROUND: Numerous studies have demonstrated that in vitro controlled enzymatic hydrolysis of fish and shellfish proteins leads to bioactive peptides. Ultrafiltration (UF) and/or nanofiltration (NF) can be used to refine hydrolysates and also to fractionate them in order to obtain a peptide population enriched in selected sizes. This study was designed to highlight the impact of controlled UF and NF on the stability of biological activities of an industrial fish protein hydrolysate (FPH) and to understand whether fractionation could improve its content in bioactive peptides. RESULTS: The starting fish protein hydrolysate exhibited a balanced amino acid composition, a reproducible molecular weight (MW) profile, and a low sodium chloride content, allowing the study of its biological activity. Successive fractionation on UF and NF membranes allowed concentration of peptides of selected sizes, without, however, carrying out sharp separations, some MW classes being found in several fractions. Peptides containing Pro, Hyp, Asp and Glu were concentrated in the UF and NF retentates compared to the unfractionated hydrolysate and UF permeate, respectively. Gastrin/cholecystokinin-like peptides were present in the starting FPH, UF and NF fractions, but fractionation did not increase their concentration. In contrast, quantification of calcitonin gene-related peptide (CGRP)-like peptides demonstrated an increase in CGRP-like activities in the UF permeate, relative to the starting FPH. The starting hydrolysate also showed a potent antioxidant and radical scavenging activity, and a moderate angiotensin-converting enzyme (ACE)-1 inhibitory activity, which were not increased by UF and NF fractionation. CONCLUSION: Fractionation of an FPH using membrane separation, with a molecular weight cut-off adapted to the peptide composition, may provide an effective means to concentrate CGRP-like peptides and peptides enriched in selected amino acids. The peptide size distribution observed after UF and NF fractionation demonstrates that it is misleading to characterize the fractions obtained by membrane filtration according to the MW cut-off of the membrane only, as is currently done in the literature. Copyright © 2010 Society of Chemical Industry

Extraction and characterisation of pepsin-solubilised collagens from the skin of bigeye snapper (Priacanthus tayenus and Priacanthus macracanthus).

Abstract: BACKGROUND: Fish collagen has been paid increasing attention as an alternative to the mammalian counterpart owing to the abundance of fish skin as a processing by-product. Generally, the low yield of collagen extracted using the typical acid solubilisation process has led to the use of mammalian pepsin as an aid for increasing the yield. Alternatively, fish pepsin, especially from tuna stomach, can be used for the extraction of pepsin-solubilised collagen (PSC). Therefore the objective of this study was to extract and characterise PSC from the skin of bigeye snapper, a fish widely used for surimi production in Thailand. RESULTS: PSCs from the skin of two species of bigeye snapper, Priacanthus tayenus and Priacanthus macracanthus, were extracted with the aid of tongol tuna (Thunnus tonggol) pepsin and porcine pepsin. PSCs from the skin of both species extracted using porcine pepsin had a higher content of β-chain but a lower content of α-chains compared with those extracted using tuna pepsin. All PSCs contained glycine as the major amino acid and had an imino acid (proline and hydroxyproline) content of 189–193 residues per 1000 residues. Transition temperatures of PSCs were in the range 30.6–31.3 °C. Fourier transform infrared spectra revealed some differences in molecular order between PSCs extracted using porcine pepsin and tuna pepsin. Nevertheless, the triple-helical structure of PSCs was not affected by pepsin digestion. Zeta potential analysis indicated that PSCs from P. tayens and P. macracanthus possessed zero net charge at pH 7.15–7.46 and 5.97–6.44 respectively. CONCLUSION: Tongol tuna pepsin could be used as a replacement for mammalian pepsin in PSC extraction. However, a slight difference in PSC properties was found. Copyright © 2009 Society of Chemical Industry

The influence of harvest time on essential oil composition, phenolic constituents and antioxidant properties of Turkish oregano (Origanum onites L.)

Abstract: BACKGROUND: The aim of this research was to determine essential oil composition, phenolic constituents and antioxidant properties of Turkish oregano (Origanum onites L.) leaves harvested during the months of June to September. RESULT: The maximum essential oil yield in the leaves appeared in the middle of July. The main components of oregano oil were carvacrol, thymol, γ-terpinene, p-cymene, α-terpinene and α-pinene. Carvacrol was highest in the July harvest. The maximum extract yield was found in September. Oil distilled from early-season (June) harvested leaves had the highest antioxidant ability, expressed as low concentration providing 50% inhibition of free radical scavenging activity and high levels of reducing/antioxidant capacity. Twelve phenolic compounds of oregano extract were identified and the main components were found to be rosmarinic acid and acecetin. The maximum rosmarinic acid and acecetin were found in harvests of July and June, respectively. Total phenolic contents, free radical scavenging activities and reducing/antioxidant capacities were found to be highest in the July harvest. DISCUSSION: All yields, chemical compositions, free radical scavenging activities and reducing/antioxidant capacities of extracts and essential oils of Turkish oregano changed importantly depending on vegetative periods of growing season. Copyright © 2009 Society of Chemical Industry

Effects of heat treatment on internal browning and membrane fatty acid in loquat fruit in response to chilling stress

Abstract: BACKGROUND: Chilling injury (CI) limits the storage period and shelf-life of red-fleshed loquat fruit (Eriobotrya japonica Lindl.), which leads to a remarkable loss after cold storage. To develop an effective technique to reduce CI, the effects of a 38 °C heat treatment in air for 5 h, plus storage at 1 °C for 35 days, on internal browning (IB) and membrane fatty acid composition of the loquat cv. Jiefangzhong were investigated. RESULTS: Heat treatment delayed the occurrence of IB and inhibited the increase of IB index in ‘Jiefangzhong’ loquat fruit. Heat treatment maintained lower levels of electrolyte leakage and malondialdehyde content, and inhibited the increases in phospholipase D and lipoxygenase activities compared with the control fruit. Meanwhile, heat treatment inhibited the increases in palmitic, stearic and oleic acid levels and delayed the decreases in linoleic and linolenic acid contents, thus maintaining higher unsaturated/saturated fatty acid ratio than the control. CONCLUSION: These results suggest that the reduction of IB in chilled loquat fruit by heat treatment might due to maintenance of membrane integrity and higher unsaturated/saturated fatty acid ratio. Copyright © 2010 Society of Chemical Industry

Effect of ethylene and 1-MCP treatments on strawberry fruit ripening.

Abstract: BACKGROUND: Strawberry is a soft fruit, considered as non-climacteric, being auxins the main hormones that regulate the ripening process. The role of ethylene in strawberry ripening is currently unclear and several studies have considered a revision of the possible role of this hormone. RESULTS: Strawberry fruit were harvested at the white stage and treated with ethephon, an ethylene-releasing reagent, or 1-methylcyclopropene (1-MCP), a competitive inhibitor of ethylene action. The effects of the treatments on fruit quality parameters and on the activity of enzymes related to anthocyanin synthesis and cell wall degradation were evaluated. Some aspects of ripening were accelerated (anthocyanin accumulation, total sugar content and increment of phenylalanine ammonia-lyase (PAL; EC 4.3.1.24) and β-galactosidase (EC 3.2.1.23) activities), while others were repressed (chlorophyll levels and increment of endo-1,4-β-glucanase (EC 3.2.1.4) and β-xylosidase (EC 3.2.1.37) activities) or unchanged (reducing sugar content, pH, titratable acidity and α-L-arabinofuranosidase (EC 3.2.1.55) activity) by ethylene. 1-MCP treatment caused the opposite effect. However, its effects were more pronounced, particularly in anthocyanin accumulation, phenolics, PAL and polygalacturonase (EC 3.2.1.15 and EC 3.2.1.67) activities. CONCLUSION: These observations probably indicate that strawberry produces low levels of ethylene that are sufficient to regulate some ripening aspects. Copyright © 2010 Society of Chemical Industry

The influence of organic/integrated production on the content of phenolic compounds in apple leaves and fruits in four different varieties over a 2‐year period

Abstract: BACKGROUND: Phenolics in fruit may be influenced by the fruit type, cultivation conditions of a plant, climatic conditions, growing season, storage conditions, and industrial processing. The aim of this study was to compare single phenolic compounds, total phenolics and antioxidant capacity of four varieties of apple grown under organic and integrated conditions over a 2-year period. RESULTS: Several different phenolic compounds belonging to the groups of hydroxycinnamic acids, flavanols, dihydrochalcones, flavonols and anthocyanins were quantified. The levels of all analysed groups of phenolics were higher (not always significantly) in the organically grown apple leaves and fruit than in the leaves or apples from integrated production. Leaves from organic trees had 10–20% higher content levels of total phenols than the leaves from trees in the integrated growing system. In both years, organic production affected the increase in the antioxidant activity of apple peel. Organic apples have higher total phenolic content than the integrated grown ones. CONCLUSION: Cultivation type had an important influence on the polyphenolic level and antioxidant capacity of the apple fruits and leaves. Apples from organic production showed a higher content of hydroxycinnamic acids, flavanols, dihydrochalcones, quercetins and total phenolics than apples from integrated cultivation. Copyright © 2010 Society of Chemical Industry

Antibacterial activities of essential oils and extracts of Turkish Achillea, Satureja and Thymus species against plant pathogenic bacteria.

Abstract: BACKGROUND: The aims of this study were to examine the chemical composition of the essential oils and hexane extracts of the aerial parts of Satureja spicigera (C. Koch) Boiss., Thymus fallax Fisch. & CA Mey, Achillea biebersteinii Afan, and Achillea millefolium L. by GC and GC–MS, and to test antibacterial efficacy of essential oils and n-hexane, chloroform, acetone and methanol extracts as an antibacterial and seed disinfectant against 25 agricultural plant pathogens. RESULTS: Thymol, carvacrol, p-cymene, thymol methyl ether and γ-terpinene were the main constituents of S. spicigera and T. fallax oils and hexane extracts. The main components of the oil of Achillea millefolium were 1,8-cineole, δ-cadinol and caryophyllene oxide, whereas the hexane extract of this species contained mainly n-hexacosane, n-tricosane and n-heneicosane. The oils and hexane extracts of S. spicigera and T. fallax exhibited potent antibacterial activity over a broad spectrum against 25 phytopathogenic bacterial strains. Carvacrol and thymol, the major constituents of S. spicigera and T. fallax oils, also showed potent antibacterial effect against the bacteria tested. The oils of Achillea species showed weak antibacterial activity. Our results also revealed that the essential oil of S. spicigera, thymol and carvacrol could be used as potential disinfection agents against seed-borne bacteria. CONCLUSION: Our results demonstrate that S. spicigera, T. fallax oils, carvacrol and thymol could become potentials for controlling certain important agricultural plant pathogenic bacteria and seed disinfectant. Copyright © 2009 Society of Chemical Industry

Fruit dry matter concentration: a new quality metric for apples.

Abstract: BACKGROUND: In the fresh apple market fruit must be crisp and juicy to attract buyers to purchase again. However, recent studies have shown that consumer acceptability could be further enhanced by improving taste. This study evaluates the use of fruit dry matter concentration (DMC) as a new fruit quality metric for apple. RESULTS: Fruit samples collected at harvest, in the two main fruit growing regions of New Zealand, showed a variation in mean fruit DMC from 130 to 156 g kg−1 with ‘Royal Gala’ and with ‘Scifresh’ from 152 to 176 g kg−1. Individual fruit DMC showed a larger range, from 108 to 189 g kg−1 with ‘Royal Gala’ and from 125 to 201 g kg−1 with ‘Scifresh’. Fruit DMC proved a more reliable predictor of total soluble solids after 12 weeks of air storage at 0.5 °C than TSS at harvest for both ‘Royal Gala’ and ‘Scifresh’. Fruit DMC was also positively related to flesh firmness, although this relationship was not as strong as that seen with soluble solids and was more dependent on cultivar. Consumer studies showed that consumer preference was positively related to fruit DMC of ‘Royal Gala’ apples. CONCLUSION: Fruit DMC can therefore be measured before or at harvest, and be used to predict the sensory potential for the fruit after storage. Copyright © 2010 Society of Chemical Industry

Exogenous γ‐aminobutyric acid alleviates oxidative damage caused by aluminium and proton stresses on barley seedlings

Abstract: BACKGROUND: Proton (H+) and aluminium (Al3+) toxicities are major factors limiting crop production on acid soils, while γ-aminobutyric acid (GABA) is a non-protein amino acid involved in various stress tolerances in plants. In this study, to determine whether exogenous GABA is functional in alleviating oxidative stress induced by H+ and Al3+ toxicities, the antioxidant defence response regulated by GABA was investigated in barley (Hordeum vulgare L.). RESULTS: After 24 h treatments of seedlings under H+, Al3+ and combined stresses with and without GABA, morphological and biochemical assays were conducted. It was observed that the inhibition of seedling root elongation caused by Al3+ and H+ toxicities was significantly mitigated by GABA. The amount of carbonylated proteins with molecular masses of 14.4–97 kDa was decreased. The activities of antioxidant enzymes were enhanced, the content of malondialdehyde was reduced and the accumulation of reactive oxygen species (ROS), as shown by staining roots with nitroblue tetrazolium, declined in GABA-treated seedlings. CONCLUSION: GABA can alleviate oxidative damage caused by H+ and Al3+ toxicities in barley seedlings by activating antioxidant defence responses and reducing the elevated levels of carbonylated proteins caused by ROS. Copyright © 2010 Society of Chemical Industry

Identification of key odor volatile compounds in the essential oil of nine peach accessions

Abstract: BACKGROUND: Volatile compounds, together with sugars and acids, are the main chemical species determining the characteristic aroma and flavor of food. In peach, more than 100 volatiles have been identified. RESULTS: The essential oil of six peach and three nectarine accessions used in Italian breeding programs was obtained by steam distillation, and the volatiles were investigated. A total of 47 known volatiles, two unidentified compounds and nine hydrocarbons were identified, including 12 aldehydes, six alcohols, three acids, three esters, six terpenes, two phenylalanine derivates, two C13 norisoprenoids, one ketone (C9) and 10 lactones. A wide variation in the number of volatiles and in their concentration was observed among the nine accessions. Twenty-one compounds presented odor activity values (OAVs) higher than 1 in at least one of the accessions and were therefore putatively considered as key odorants in the peach volatile composition. CONCLUSION: This study reports the identification, quantification and potency, based on the OAVs, of the most important volatile compounds, along with fruit quality characteristics, of nine different peach/nectarine accessions and will help future peach volatile breeding programs for the selection of odor-rich accessions to be used in the development of new improved cultivars. Copyright © 2010 Society of Chemical Industry

Chemical characteristics and antioxidant activities of polysaccharide purified from the seeds of Plantago asiatica L.

Abstract: BACKGROUND: A water-soluble polysaccharide from the seeds of Plantago asiatica L. (P. asiatica L. polysaccharide, PLP) was extracted with hot water and purified by gel filtration chromatography. The chemical characteristics of PLP were determined by high-performance gel permeation chromatography (HPGPC) and Fourier transform infrared (FTIR) spectroscopy. In addition, the antioxidant activities of PLP in vitro were evaluated using various test systems, including scavenging of 1,1-diphenyl-2-picryl-hydrazyl (DPPH) radicals, scavenging of superoxide radicals generated by 1,2,3-phentriol autoxidation, scavenging of hydroxyl radicals and inhibition of lipid peroxidation. RESULTS: The molecular weight of PLP was determined by HPGPC to be about 1894 kDa. PLP contained 29.2 g kg−1 protein and 145.8 g kg−1 uronic acid. The FTIR spectrum of PLP also revealed typical characteristics of a polysaccharide containing protein and uronic acid. Moreover, the results showed that PLP possessed antioxidant activities, but lower than those of ascorbic acid. CONCLUSION: PLP is an acid protein-bound polysaccharide of high molecular weight, but its structure needs further study. The present results suggest that PLP could potentially be used as a natural antioxidant. Copyright © 2009 Society of Chemical Industry

Root colonisation by the arbuscular mycorrhizal fungus Glomus intraradices alters the quality of strawberry fruits (Fragaria × ananassa Duch.) at different nitrogen levels

Abstract: BACKGROUND: Arbuscular mycorrhizal fungi (AMF) increase the uptake of minerals from the soil, thus improving the growth of the host plant. Nitrogen (N) is a main mineral element for plant growth, as it is an essential component of numerous plant compounds affecting fruit quality. The availability of N to plants also affects the AMF – plant interaction, which suggests that the quality of fruits could be affected by both factors. The objective of this study was to evaluate the influence of three N treatments (3, 6 and 18 mmol L −1 ) in combination with inoculation with the AMF Glomus intraradices on the quality of strawberry fruits. The effects of each factor and their interaction were analysed. RESULTS: Nitrogen treatment significantly modified the concentrations of minerals and some phenolic compounds, while mycorrhization significantly affected some colour parameters and the concentrations of most phenolic compounds. Significant differences between fruits of mycorrhizal and non-mycorrhizal plants were found for the majority of phenolic compounds and for some minerals in plants treated with 6 mmol L −1 N. The respective values of fruits of mycorrhizal plants were higher. CONCLUSION: Nitrogen application modified the effect of mycorrhization on strawberry fruit quality. c � 2010 Society of Chemical Industry

Antioxidant activity and phenolic content of wine vinegars produced by two different techniques

Abstract: BACKGROUND: The presence of phenolics in fruit, red wine and vinegar has positive health effects due to their significant antioxidant activity. The aim of the study was to determine the effects of two different vinegar production methods on antioxidant activity and phenolic level of vinegars derived from Ulugbey Karasi grapes. Traditional surface and industrial submerge methods were used to make vinegar. Samples were taken from fresh red grape juice, maceration, wine, traditional vinegar and industrial vinegar. RESULTS: Total phenolic content of traditional and industrial vinegar samples were 2690 mg L−1 and 2461 mg L−1 GAE, respectively. ORAC values of traditional and industrial vinegar samples were 10.50 µmol mL−1and 8.84 µmol mL−1 TE, respectively. Antioxidant activity values of traditional and industrial vinegars were 13.50 mmol L−1 and 10.37 mmol L−1 TEAC, respectively. Gallic acid, catechin, epicatechin, chlorogenic acid, caffeic acid, syringic acid, p-coumaric acid and ferulic acid were detected in grape juice, wine and vinegar samples. The content of catechin in industrial vinegar (27.50 mg L−1) was significantly higher than that of in traditional vinegar (13.76 mg L−1) (P 0.05). CONCLUSION: Results of this study showed that different production methods affected the functional constituents of wine vinegars. Copyright © 2010 Society of Chemical Industry