Quality of Swiss chard produced by conventional and organic methods

The storage lives of Swiss chard produced by conventional and organic methods was investigated. No significant differences were found in the initial populations of yeast, molds (1–3×10⁴ CFU/g) and psychrotrophic (1×10⁴–1.5×10⁵ CFU/g), mesophilic (4×10³–5×10⁴ CFU/g) and lactic acid bacteria (2×10² and 1.5×10³ CFU/g). The evolutions of the population of those microorganisms during storage were also similar for both chards. First-order kinetics after an induction period were found for the degradation of ascorbic acid. Although the rate constant (0.057 days^–1) was similar for both chard, the induction period for organic chard (∼10 days) was longer than for conventional chard (∼3 days). No significant differences were found between the water and chlorophyll contents and in pH and titratable acidity of both chards. Sensorial analysis showed that organically produced chard retained turgidity, color and brightness longer than the conventionally produced chard.     

The sensory quality of foods produced by conventional and enhanced cook-chill methods

Cook-chill systems are now widely used within the catering industry. The basic method has been enhanced by the use of vacuum packaging to extend shelf-life; and, it is claimed, sensory quality. This paper reviews the literature available on the sensory quality of foods produced by conventional and enhanced cook-chill methods. It shows that the sensory quality of foods produced by these methods has received little attention from researchers, despite, in the case of methods using vacuum packaging, some extravagant claims about improved eating quality. Most attention has been paid to meat products. Deteriorative changes are shown to occur rapidly, but many variables affect the end result, which is often product and process specific. Lack of standardization, both in the catering industry and in experimental methods, makes comparisons between studies difficult.     

Influence of culture on social representation of wines produced by various methods: Natural,organic and conventional

The overall aim of the present study was to investigate the social representation of wines produced by various methods of wine production, in particular in relation to the concept of Distance to the Object (DO). The DO concept postulates that some participants will have a greater knowledge of the object (wine), feel more involved with it, and develop more practices related to wine, than other participants. We compared the social representations of French and New Zealanders of two levels of domain specific expertise (wine professionals; wine consumers) concerning three wine types, natural wine, organic wine, and conventionally-produced wine. Via a preliminary study, we validated our DO questionnaire. In the main analysis, results demonstrated French participants to have a higher level of involvement in wine than New Zealanders, and professionals to have higher levels on involvement, personal identification and capacity for action than consumers. New Zealanders expressed more knowledge and levels of practices than the French, and professionals more than consumers did. Results also showed that organic wine produced the most structured representations (i.e., participants more often quoted the same words) followed by natural wines, with conventional-wine representation the least structured. French participants’ representations were more structured than New Zealanders, and consumers’ representations more structured than those of professionals. Finally, by drawing on data concerning the frequencies, rank and valence of the words evoked by participants, we demonstrated differences in the content of participants’ social representations as a function of wine-production method, culture, and level of domain-specific expertise, demonstrating how these variables influence wine representation.     

Comparing the fatty acid composition of organic and conventional milk

During a 12-mo longitudinal study, bulk-tank milk was collected each month from organic (n = 17) and conventional (n = 19) dairy farms in the United Kingdom. All milk samples were analyzed for fatty acid (FA) content, with the farming system type, herd production level, and nutritional factors affecting the FA composition investigated by use of mixed model analyses. Models were constructed for saturated fatty acids, the ratio of polyunsaturated fatty acids (PUFA) to monounsaturated fatty acids, total n-3 FA, total n-6 FA, conjugated linoleic acid, and vaccenic acid. The ratio of n-6:n-3 FA in both organic and conventional milk was also compared. Organic milk had a higher proportion of PUFA to monounsaturated fatty acids and of n-3 FA than conventional milk, and contained a consistently lower n-6:n-3 FA ratio (which is considered beneficial) compared with conventional milk. There was no difference between organic and conventional milk with respect to the proportion of conjugated linoleic acid or vaccenic acid. A number of factors other than farming system were identified which affected milk FA content including month of year, herd average milk yield, breed type, use of a total mixed ration, and access to fresh grazing. Thus, organic dairy farms in the United Kingdom produce milk with a higher PUFA content, particularly n-3 FA, throughout the year. However, knowledge of the effects of season, access to fresh grazing, or use of specific silage types could be used by producers to enhance the content of beneficial FA in milk.     

Phenolic composition of wine vinegars produced by traditional static methods

Phenolic composition of wine vinegars produced in a zone placed in the South of Spain, El Condado de Huelva, has been studied by HPLC coupled with a photodiode array detector and direct injection of the sample. A few compounds not identified in other traditional wine vinegars (Sherry wine vinegars) have been found. Criteria to distinguish those vinegars from Sherry wine vinegars are reported.     

Content and composition of non-starch polysaccharides in some norwegian plant foods

Analyses of non-starch polysaccharides have been carried out on plant material grown in Norway including potatoes, apples and some vegetables.A method which determined both amount and type of polysaccharides was used.     

Review on the main differences between organic and conventional plant‐based foods

The present review reports on the main characteristics and properties of plants cultivated following organic and conventional procedures, in the attempt to clarify give a deeper insight into some possible differences and to compare the two cultivation procedures. Here, we summarise research results regarding nutritional and safety properties of vegetable foods, evidencing qualitative differences observed between the two cultivation methods. It appears that the intake of organic foods leads to some advantages, such as the ingestion of a higher content of phenolic compounds and some vitamins, such as vitamin C, and a lower content of nitrates and pesticides. From literature, it appears that a special care should be taken about the ingestion of foods in relation to the content of some substances, e.g. polyamines, substances stimulating cellular division, because some foods coming from organic origin present a higher content of these compounds, which could explain some of the effect of the diet on patients affected by certain syndromes.     

Lipid composition of retailed organic, free-range and conventional chicken breasts

Lipid fractions of 20 retailed chicken breasts were correlated with production system: organic, corn‐fed, free‐range and conventional. Neutral lipid (NL), phospholipid (PL) and free fatty acids (FFA) were examined separately. Influence of production systems was found more pronounced in PL composition than NLs. Corn‐fed and free‐range NLs had higher contents of nutritionally beneficial eicosapentanoic acid (C20:5 n‐3) and docosahexanoic acid (C22:6 n‐3) than organic and conventional. Lower polyunsaturated fatty acids in organic and free‐range PLs could be beneficial for tissue stability. Principal component product space for PLs showed clear clustering related to product category. In contrast, this was not observed with FFA except in the partial least square regression product space suggesting influences on NLs and PLs and FFA. PLs had lower contents of arachidonic acid than in earlier studies. Advantages were observed in lipid fractionation using advanced sorbent extraction matrices.     

Fat composition of organic and conventional retail milk in northeast England

This study of UK retail milk identified highly significant variations in fat composition. The survey, conducted over 2 yr replicating summer and winter, sampled 22 brands, 10 of which indicated organic production systems. Results corroborate earlier farm-based findings considering fat composition of milk produced under conventional and organic management. Organic milk had higher concentrations of beneficial fatty acids (FA) than conventional milk, including total polyunsaturated fatty acids (PUFA; 39.4 vs. 31.8 g/kg of total FA), conjugated linoleic acid cis-9,trans-11 (CLA9; 7.4 v 5.6 g/kg of FA), and α-linolenic acid (α-LN; 6.9 vs. 4.4 g/kg of FA). As expected, purchase season had a strong effect on fat composition: compared with milk purchased in winter, summer milk had a lower concentration of saturated fatty acids (682 vs. 725 g/kg of FA) and higher concentrations of PUFA (37.6 vs. 32.8 g/kg of FA), CLA9 (8.1 vs. 4.7 g/kg of FA), and α-LN (6.5 vs. 4.6 g/kg of FA). Differences identified between sampling years were more surprising: compared with that in yr 2, milk purchased in year 1 had higher concentrations of PUFA (37.5 vs. 32.9 g/kg of FA), α-LN (6.0 vs. 5.1 g/kg of FA), and linoleic acid (19.9 vs. 17.5 g/kg of FA) and lower concentrations of C16:0 and C14:0 (332 vs. 357 and 110 vs. 118 g/kg of FA, respectively). Strong interactions were identified between management and season as well as between season and year of the study. As in the earlier farm studies, differences in fat composition between systems were greater for summer compared with winter milk. Large between-year differences may be due to changes in weather influencing milk composition through forage availability, quality, and intake. If climate change predictions materialize, both forage and dairy management may have to adapt to maintain current milk quality. Considerable variation existed in milk fat composition between brands.     

Evaluation of methods of analysis for dietary fibre using real foods and model foods

Rationale and objectives

There are several rational and empirical methods for the measurement of dietary fibre and its components. A selection of these methods were evaluated by investigation of a range of real foods and model foods with added resistant starch (RS), non-starch polysaccharides (NSP) and resistant oligosaccharide (RO) ingredients.

Methods

A range of rational methods were applied in determining specific carbohydrate constituents: RS, NSP and RO, including fructans. For comparison, empirical methods AOAC 991.43 (2001.03) and AOAC 2009.01 were applied, based on determination of gravimetric residues for high molecular weight and size-exclusion HPLC analysis of the ethanol filtrate for low molecular weight components.

Results

In general there was agreement between different rational methods for the analysis of RS and fructans, though there were notable exceptions for some product types. Comparison of methods for total RS and those that only measure the RS3 fraction, from retrograded starch, indicated that RS3 was the only type present for most processed products. This also explains the similar results obtained by AOAC 991.43 (2001.03) and AOAC 2009.01, though the latter is intended to recover other RS types as well. For many products there was agreement between results obtained by rational and empirical methods, though there were exceptions and the reasons for these are discussed.

Conclusion

Rational and empirical methods can both be used to determine dietary fibre in most situations. The information provided by rational methods is useful in identifying the specific carbohydrate constituents present in foods and can assist in determining whether added extracted and synthesised ingredients are ones that conform to the Codex and EU dietary fibre definition.     

Phenolic composition and nutraceutical properties of organic and conventional cinnamon and peppermint

Conventional and organic cinnamon and peppermint were investigated for their phenolic profile, anti-proliferative, anti-inflammatory, and antioxidant properties. Accelerated solvent extraction with 75% acetone was used to extract samples. Caffeic acid was the most abundant phenolic acid in peppermint. Catechin, (−)-epigallocatechin gallate, syringic acid, gallic acid, vanillic acid, and p-coumaric acid were also detected in both spices. There was no significant difference between conventional and organic spices in the composition of most individual phenolics. All conventional and organic peppermint and cinnamon extracts exhibited strong anti-proliferative and anti-inflammatory properties. Cinnamon was more efficient in inhibiting IL-1β and COX-2 expression, while peppermint showed better inhibitory effect on IL-6 and MCP-1. This study indicates that cinnamon and peppermint may potentially be used as dietary sources of bioactive phytochemicals for improving health.     

Design of volatile organic compounds profiles of roasted Coffea arabica extracts produced by supercritical and conventional solvents

This work addresses the potential of supercritical fluid extraction (SFE) to design volatile organic compounds (VOCs) profiles using roasted Coffea arabica. On the whole, 57 VOCs were identified by HS-SPME/GC–MS. A full factorial design was adopted to study the effect of pressure (180 and 300 bar), temperature (40 and 80 °C) and ethanol content (0 and 5 wt.%). The total extraction yield ranged from 1.4 wt.% to 9.8 wt.%. At 180 bar and 80 °C, two extracts exhibited VOCs amount up to 3.5 times higher than the dichloromethane extract. Temperature and pressure favoured VOCs amount and total yield in conflicting ways, and ethanol had a negligible effect on VOCs amount. At 180 bar and 80 °C, the VOCs profile revealed a reinforcement of pyrroles, phenols, cyclopentenes and pyrans, at the expense of pyridines, carboxylic acids and furans. Hence, this essay evidences the potential of SFE to engineer coffee VOCs profiles.     

Fatty acid composition of certified organic,conventional and omega-3 eggs

The objective of this study was to compare the fatty acid composition of commercially available conventional, certified organic, and omega-3 eggs. Egg components were assessed, and the fatty acid composition of yolk lipids was determined by gas chromatography. Organic egg yolk contained a higher percentage of palmitic and stearic acids than did conventional yolk (P < 0.05) with no differences observed in the monounsaturated or polyunsaturated fatty acid compositions. Compared with organic and conventional eggs, omega-3 egg yolk contained lower percentages of myristic and palmitic acids, and higher omega-3 fatty acids. In a sub-analysis of conventional egg types, the percent of stearic acid in “cage” egg yolk was significantly lower (P < 0.05) than those of “barn-laid” and “free-range” eggs. “Cage” eggs had a significantly lower percentage (P < 0.05) of arachidonic acid than had “barn-laid” eggs. Consumption of omega-3 eggs has the potential to confer health benefits through the increase in intake of omega-3 fatty acids. With regard to organic or conventional methods of production, the small differences in saturated fatty acids observed in the present study are unlikely to have any significant metabolic effect on the consumer.     

Evaluation of viral extraction methods on a broad range of Ready-To-Eat foods with conventional and real-time RT-PCR for Norovirus GII detection

Noroviruses (NoV) are a common cause of foodborne outbreaks. In spite of that, no standard viral detection method is available for food products. Therefore, three viral elution-concentration methods and one direct RNA isolation method were evaluated on a broad range of Ready-To-Eat (RTE) food products (mixed lettuce, fruit salad, raspberries and two RTE dishes) artificially seeded with a diluted stool sample contaminated with NoV genogroup II. These seeding experiments revealed two categories of RTE products, fruits and vegetables grouped together and RTE dishes (penne and tagliatelle salads) which are rich in proteins and fat formed another category. The RNA extracts were amplified and detected with two conventional RT-PCR systems (Booster and Semi-nested GII) and one real-time RT-PCR (Real-time GII) assay. A fast direct RNA isolation method detected 10(2) RT-PCRU on 10 g penne and tagliatelle salads with the conventional RT-PCR assays. However real-time RT-PCR was less sensitive for penne salad. A viral elution-concentration method, including a buffer solution for the elution step and one polyethylene glycol (PEG) precipitation step, was able to detect 10(2) RT-PCRU on 50 g frozen raspberries with conventional and real-time RT-PCR assays. Moreover the latter extraction method used no environmental hazardous chemical reagents and was easy to perform.     

Phenolic compounds and fatty acid composition of organic and conventional grown pecan kernels

BACKGROUND: In this study, differences in contents of phenolic compounds and fatty acids in pecan kernels of organically versus conventionally grown pecan cultivars (Cheyenne, Desirable, and Wichita) were evaluated. RESULTS: Although nine phenolic compounds (gallic acid, catechol, catechin, epicatechin, m‐coumaric acid, chlorogenic acid, ellagic acid, caffeic acid and an ellagic acid derivative) were identified in the methanol extract (80% methanol) of defatted kernels, only three compounds (gallic acid, catechin and ellagic acid) existed in sufficient amounts to accurately quantify levels in different cultivars and to study differences in organic versus conventional cultivation. Levels of ellagic acid and catechin found in organically grown ‘Desirable’ were fourfold and twofold higher than in conventional samples, respectively. Furthermore, significant differences in these two compounds were also observed when comparing values between cultivars. Oil content was also significantly greater only in organically grown ‘Desirable’. Oleic acid was the major fatty acid present and its content was significantly higher in organically versus conventionally grown ‘Desirable’ pecans, while there was no difference in levels of oleic acid in ‘Wichita’ and ‘Cheyenne’. On the other hand, linoleic acid content was significantly less in organically versus conventionally grown ‘Desirable’ pecans. CONCLUSION: Overall, these results showed that the effects of cultural differences (i.e. organic versus conventional cultivation) on kernel composition largely depend on the type of pecan cultivar. Copyright © 2009 Society of Chemical Industry     

植物源性食物中活性肽氨基酸组成的研究进展

植物源性食物中含有丰富的活性肽,其中抗氧化肽,降压肽,免疫调节肽,抗肥胖肽,抗胆固醇肽,抗肿瘤肽,阿片肽,抗血栓肽等均已被广泛研究报道。该文从肽序列的氨基酸组成入手,综述了目前已鉴定出氨基酸序列的植物源性食物中的各种生物活性肽,以为此类活性肽的进一步研究应用提供参考。     

Influence of conventional and organic agricultural practices on the phenolic content in eggplant pulp: Plant-to-plant variation

Consumer awareness, pesticide and fertiliser contaminations, and environmental concerns have resulted in significant demand for organically grown farm products. The present study evaluates the influence that organic and conventional farming practices exert on the total phenolic content in eggplant samples from two cultivars, Blackbell (American eggplant) and Millionaire (Japanese eggplant), grown by conventional and organic farming practices with similar climatic conditions. In addition, plant-to-plant variation in phenolic content was determined from eight eggplant samples collected from different plants grown at various field positions. Samples were separately assayed for phenolic content by the two independent procedures, HPLC/LC–MS and Folin–Ciocalteu assay. The results of the HPLC analysis showed significant plant-to-plant variation (% RSD ranged from 22% to 48%) in 5-caffeoylqunic acid content (the most abundant phenolic acid) in eight eggplant samples collected from eight different plants belonging to the same cultivar and grown under similar conditions. The cv. Millionaire showed a higher total phenolic content compared to the Blackbell cultivar. We did not observe significant consistent trend in the phenolic content of eggplant samples grown with organic and conventional farming practices with both eggplant cultivars. We, however, observed a strong correlation (R² = 0.87) between total phenolic content as assayed by Folin–Ciocalteu assay and 5-caffeoylqunic acid, a major phenolic acid in eggplant extract. This study concludes that multiple repetitive analyses of plant products collected from different plants grown over various time periods (seasons) at different locations should always be carried to unambiguously prove the impact of growing conditions on phenolic content or antioxidant activity.     

Polyphenolic profile and antioxidant activity of five apple cultivars grown under organic and conventional agricultural practices

The polyphenols and total antioxidant activities of five apple cultivars, grown by organic and conventional agricultural methods in neighbouring farms, were determined and compared. Total polyphenols in the whole fruit and in the peel were determined by the Folin-Ciocalteu method, and the total antioxidant activity was determined by three established methods, diphenyl picrylhydrazyl (DPPH), azinobis (3-ethylbenzthiazoline-6-sulfonic acid) (ABTS) and ferric reducing/antioxidant power (FRAP). Polyphenolic content for the whole fruit was in the range of 80–196 and for the peel 165–400 (mg Gallic Acid Equivalent (GAE)/100 g fresh weight) for both types of agricultural practices. Antioxidant activities of fruit extracts were also relatively similar and well correlated to their polyphenolic content. High-performance liquid chromatography (HPLC) analysis of the most important polyphenolics (chlorogenic acid, catechin, epicatechin, procyanidin B1 and B2, cyaniding 3-galactoside, phloridzin, quercetin 3-galactoside and quercetin 3-arabinoside) also showed that concentrations do not differentiate significantly between the organic and conventional apples. Statistical significance of differences in antioxidant activities among the same cultivars was relatively small (flesh + peel or peel only) for both types of apples. These results indicate that organic apples do not present higher antioxidant or nutritional value compared with conventionally grown ones, as far as polyphenolic content and total antioxidant activities are concerned.