Journal of the Science of Food and Agriculture

Reid, David S; Scoffield, Sarah

doi: 10.1002/jsfa.3449pmid: N/A

doi: 10.1002/jsfa.3444pmid: N/A

Polovic, Natalija Dj; Pjanovic, Rada V; Burazer, Lidija M; Velickovic, Sava J; Jankov, Ratko M; Cirkovic Velickovic, Tanja D

doi: 10.1002/jsfa.3404pmid: N/A

BACKGROUND: It is thought that food sensitisers must be able to reach the intestine in order to sensitise patients. Pectin is a gel‐forming plant polysaccharide that can protect allergens from in vivo gastric digestion and in vitro pepsin digestion. The aim of this study was to examine if pectin gel formed in the acidic environment of the stomach can protect labile allergen from in vitro gastrointestinal digestion. RESULTS: Pectin forms a gel in the acidic conditions of gastric fluid up to a concentration of 1.0 ± 0.14 g L−1. Four allergenic fruits (kiwi, cherry, apple and banana) form gels in the same manner at the dilutions 14.8 ± 0.4; 8.4 ± 0.2, 9.4 ± 0.35 and 29.1 ± 0.2, respectively. The time necessary for dissolution of 50 g L−1 pectin gel in intestinal fluid was found to be 70 ± 0.2 min. Pectin gel formed in situ was able to protect Act c 1 from pepsin digestion for 1 h and from further intestinal digestion for one additional hour. CONCLUSION: Pectin gel in an acidic environment protects Act c 1 from pepsin digestion and dissolves slowly in the slightly basic environment of the intestine allowing the survival of fruit allergen for additional time and possible interaction with the gut immune system. Copyright © 2008 Society of Chemical Industry

González‐Aguilar, Gustavo A; Valenzuela‐Soto, Elisa; Lizardi‐Mendoza, Jaime; Goycoolea, Francisco; Martínez‐Téllez, Miguel A; Villegas‐Ochoa, Mónica A; Monroy‐García, Imelda N; Ayala‐Zavala, J Fernando

doi: 10.1002/jsfa.3405pmid:

Campbell, Rachel L.; Smith, Bronwen G.; Jaeger, Sara R.; Harker, F. Roger

doi: 10.1002/jsfa.3406pmid: N/A

BACKGROUND: Consumers often express concern about the quality of fruit available to buy and the rate at which it deteriorates in their homes. Despite this there are few studies on quality of fruit collected from consumers. This study considered three questions: (1) what was the quality of fruit in retail stores and how did it vary over the study period? (2) What was the extent that fruit quality deteriorated in consumers' homes? (3) Were there any consumer behaviours or attitudes that extenuated or mitigated the effects of fruit deterioration in the home? RESULTS: The quality of fruit purchased from the supermarkets was above what would be considered commercially acceptable, but varied in a non‐systematic fashion across the study period. The fruit in consumers' homes was of slightly lower physical quality than that purchased from the supermarkets, and the deterioration in quality was as would be expected as fruit ripens. Even so, 28% of consumers indicated that they dispose of fruit each week. This occurred despite many of them having strategies to minimise wastage. CONCLUSION: Despite the deterioration and wastage of fruit, the consumers in this study did not appear overly concerned and some even took ownership for the poor quality of fruit in their home. Copyright © 2008 Society of Chemical Industry

Wiese, Stefanie; Gärtner, Sonja; Rawel, Harshadrai M.; Winterhalter, Peter; Kulling, Sabine E.

doi: 10.1002/jsfa.3407pmid: N/A

BACKGROUND: Recent studies indicate that the bioavailability of anthocyanins is extremely low. One of the possible reasons could be their binding to proteins. Therefore, the binding affinity of cyanidin‐3‐glucoside (Cy3glc) to HSA and α‐amylase was investigated by the quenching of protein tryptophan fluorescence. From data obtained, the binding constants and the free Gibbs energy were calculated. The changes in conformation of the proteins tested were studied with circular dichroism and the influence of binding on α‐amylase activity determined. RESULTS: Cy3glc quenched the tryptophan fluorescence and upon ligand binding a change in protein structure was observed related to the corresponding decrease in the α‐amylase activity. The association constants of 25 to 77 × 103 L mol−1 were calculated for different proteins, indicating weak interactions of non‐covalent nature. Competitive binding with HSA in the presence of 8‐anilino‐1‐naphthalene sulfonic acid suggest involvement of hydrophobic interactions, in the case of HSA the possible site being subdomain IIA. CONCLUSION: The strongest affinity of Cy3glc for HSA being at pH 7 underlines its potential in transport and distribution of the phenolic compounds in organisms. An influence on salivary amylase activity is possible when drinking berry juices with high anthocyanins content. Copyright © 2008 Society of Chemical Industry

Dawo, Mohamed I; Wilkinson, J Michael; Pilbeam, David J

doi: 10.1002/jsfa.3408pmid: N/A

BACKGROUND: Intercropping maize (Zea mays L.) with common bean (Phaseolus vulgaris L.) can give silage yields that are as high as with monocropped maize, but with more crude protein. Interactions between maize and common bean intercropped in the UK were assessed at a range of plant densities (maize 100 000, 75 000 and 50 000 plants ha−1 and beans at a fixed density of 50 000 plants ha−1). RESULTS: In monoculture, maize yield per plant increased as planting density decreased from 100 000 to 50 000 plants ha−1. At a density of 50 000 maize plants ha−1, both dry weight yield per plant and shoot N concentrations of maize were greater when intercropped with 50 000 Type III (bush‐type) bean plants ha−1 than in monoculture (196.4 g plant−1 and 167.0 g plant−1; 21.6 g N kg−1 dry mass and 17.4 g N kg−1 dry mass, respectively), but intercropping Type IV (climbing) beans at this density combination had no effects on either maize plant weight or shoot N concentration. Invariably, however, the beans grown at 50 000 plants ha−1 were adversely affected by competition with maize at all densities. Weight per plant of both Type III (bush‐type) and Type IV (climbing) beans grown in competition with 50 000 maize plants ha−1 was only about half that of when grown alone. Intercropping gave increased mycorrhizal colonization of both species, especially in unfertilized plots, and gave a higher shoot N concentration in the maize. The beans had more nodules in the intercrop than in the monocrop. CONCLUSIONS: Intercropping maize with Type III common bean at 50 000 plants of each species ha−1 increases yield per maize plant above that of monoculture maize at 50 000 plants ha−1, despite plant density being doubled. This increase is brought about by increased maize shoot N concentration. Mycorrhizal infection of both species, and bean plant nodulation, are stimulated, and N moves from the beans to the maize. Copyright © 2008 Society of Chemical Industry

Agbenin, John O.; Danko, M; Welp, Gerphard

doi: 10.1002/jsfa.3409pmid: N/A

BACKGROUND: Human exposure to heavy metals is attributed to consumption of vegetables raised in polluted soil environment. We examined the concentrations of As, Cd, Co, Cr, Cu, Ni, Pb and Zn in soils and lettuce (Latuca sativa) and amaranthus (Amaranthus caudatus) in 15 garden fields under long‐term wastewater irrigation. RESULTS: The concentrations of As (0.3–2.1 mg kg−1), Cd (0.07–0.3 mg kg−1), Co (4.6–9.1 mg kg−1) and Cr (21.6–36.2 mg kg−1) in the gardens were consistent with background concentrations in soils, but Ni (12.6–25.7 mg kg−1), Cu (12.5–24.6 mg kg−1), Pb (25.7–71.6 mg kg−1) and Zn (52.3–158 mg kg−1) concentrations were double the concentrations normally encountered in arable fields in the region. The concentrations of Cd and As in the vegetables were within safe limits, but Co (0.14–0.67 mg kg−1 fresh weight (fw)) and Ni (1.0–2.7 mg kg−1 fw) concentrations in lettuce were relatively high for leaf vegetables. The concentration of Pb (0.65–4.80 mg kg−1 fw) was above safe limit of 0.3 mg kg−1 fw, while the concentrations of Cu (1.3–2.7 mg kg−1 fw and Zn (10.2–23.6 mg kg−1 fw) were close to the unsafe limits for leaf vegetables. There were no strong linear correlations between soil metal concentrations and bio‐concentrations in the vegetable crops. CONCLUSION: We surmise that leaf vegetables can accumulate metals in their tissues to unsafe levels even when total metal concentrations in these soils are below the allowable concentrations in agricultural soils. Copyright © 2008 Society of Chemical Industry

Garnica, Maria; Houdusse, Fabrice; Yvin, Jean Claude; Garcia‐Mina, Jose Maria

doi: 10.1002/jsfa.3410pmid: N/A

BACKGROUND: Some authors suggest that nitrate improves the effects of ammonium and urea nutrition on plant growth via an increase in both the root uptake of ammonium and urea, and the further activation of its assimilation. In order to verify these hypotheses, wheat (Triticum aestivum L.) seedlings were grown with various nitrogen supplies containing the main nitrogen forms (ammonium, nitrate and urea). Root nitrogen uptake and the concentration of each of the nitrogen forms in roots and shoots were studied. RESULTS: Results indicated that nitrate increases root uptake of ammonium and urea, with this effect being highly significant when the three nitrogen forms are supplied simultaneously. Nitrate significantly increased both urea and ammonium assimilation in the shoot of plants fed urea‐and‐nitrate. However, nitrate did not significantly affect ammonium assimilation in either shoots or roots in plants fed ammonium‐and‐nitrate. CONCLUSION: The beneficial effect of nitrate seems to be related to an enhancement of root uptake of ammonium and urea, although their assimilation was significantly increased in urea‐fed plants, but not in ammonium‐fed plants. Copyright © 2008 Society of Chemical Industry

Bonvehí, J Serra; Gutiérrez, A Lacalle

doi: 10.1002/jsfa.3411pmid: N/A

BACKGROUND: The aim of this work was to ensure that Label Basque market honey is free of veterinary residues. RESULTS: A total of 567 Basque honey samples were previously analyzed with the respective Charm II system—68 samples were presumptive positive for sulfonamides (SA‐s), 24 samples for tetracyclines (TC‐s), and no positive samples for chloramphenicol (CAP) (<0.3 µg kg−1) residues. The residues were mostly confirmed by liquid chromatography fluorescence detection (LC‐FD) and tandem mass spectrometry (LC‐MS/MS), according to the latest European Union criteria for the analyses of veterinary drug residues (2002/657/EC). These techniques confirmed that 19 of the 68 samples, presumptive contaminated with SA‐s, contained sulfathiazole (STZ) residues at levels from 20 to 210 µg kg−1, and the 24 samples presumptive contaminated with TC‐s, were also confirmed, showing tetracycline (TC) levels from 15 to 920 µg kg−1. Linearity range, decision limit (CCα), detection capability (CCβ), precision and reproducibility were also determined. CONCLUSION: Residues of veterinary drugs were confirmed in a very limited number of honey samples: sulfathiazole (3.40%) and tetracycline (4.22%). This work reports the advantages of the Charm II assay, but also its limitations, detecting SA‐s in most (87.7%) of the heather (Erica vagans) honey samples. The false positives detected in this honey were assumed to be of an unknown compound that has not been confirmed as a drug residue. Until now, no studies have been performed to find out if other heather honeys of different geographical origins give similar false positives for SA‐s. Copyright © 2008 Society of Chemical Industry