Application of a statistical approach to the classification of honey by geographic origin

Forty eight honeys from the La Rioja region of Spain were analysed to establish their quality. Fourteen legally required parameters of quality control were measured. Samples were obtained from two geographic areas of production: Valley and Sierra. These areas present different agroclimatic conditions and, thus, different flora. Classification of these honeys according to their geographic origin was achieved by applying multivariate statistical analysis to the chemical and physical data. Acidity (free acidity and pH), mineral content (electrical conductivity and ash) and factors related to degree of freshness (hydroxymethylfurfural and diastatic activity), were found to be the most important features for classification. Determination of the geographic origin of a La Rioja honey (Valley or Sierra) was possible with 83% accuracy using only these legally required quality control parameters; pollen studies were not necessary to achieve this objective.     

Ileal digestibility of defatted soybean,lupin and chickpea seed meals in cannulated Iberian pigs: II. Fatty acids and carbohydrates

Five castrated male Iberian pigs (100 ± 2 kg mean live body weight) fitted with T‐shaped ileal cannulas were used to determine ileal digestibility of legume seed meals. The diets were based on defatted soybean (256 g kg^?1), lupin (451 g kg^?1) or chickpea (731 g kg^?1) seed meals and contained similar amounts of digestible energy (14.2–15.1 kJ g^?1) and protein (107 g kg^?1). Only myristic acid (C14:0) ileal apparent digestibility was higher (p < 0.05) in lupin than in chickpea meal. Ileal apparent digestibility of unsaturated fatty acids (FA) (710–920 g kg^?1) was higher (p < 0.05) than that of saturated (480–710 g kg^?1) FA for both seed meals. Ileal digestibility of chickpea starch was 850 g kg^?1. Ileal digestibility of oligosaccharides (sucrose, raffinose, stachyose, verbascose and ciceritol) in lupin (820 g kg^?1) and chickpea (690 g kg^?1) was higher (p < 0.05) than that of defatted soybean (510 g kg^?1). However, total amounts of oligosaccharides digested were higher (p < 0.05) for lupin and chickpea meals (29.6 and 24.6 g kg^?1 feed respectively) than for soybean (15.2 g kg^?1 feed). Among individual non‐starch polysaccharide (NSP) sugars, ileal digestibility values for rhamnose and xylose in lupins were higher (p < 0.05) than those for soybean or chickpea. Ileal digestibility of lupin meal NSP (650 g kg^?1) was higher (p < 0.05) than those of soybean (560 g kg^?1) or chickpea (430 g kg^?1). Up to the terminal ileum, higher (p < 0.05) amounts of lupin total NSP (94.1 g kg^?1) than for soybean (24.3 g kg^?1) or chickpea (27.1 g kg^?1) were digested. Lactate, acetate and isobutyrate concentrations were higher (p < 0.05) in ileal contents of pigs fed lupin and chickpea seed meals compared with soybean‐fed animals. It is concluded that higher lactate and short chain fatty acids concentrations in ileal contents of pigs fed lupin or chickpea seed meals compared with soybean are likely to be the result of higher total amounts of lupin NSP and/or lupin and chickpea oligosaccharides digested up to the terminal ileum. This might have a protective effect on Iberian pig's intestinal physiology. Both lupin and chickpea meals are likely to constitute a valuable alternative to defatted soybean in Iberian pig feeding. Copyright © 2005 Society of Chemical Industry     

Influence of recovery conditions on apparent heat resistance of Bacillus stearothermophilus spores

The effects of post-treatment environmental factors on the heat resistance of Bacillus stearothermophilus spores (ATCC 12980, 7953, 15951 and 15952) were investigated. Nutrient Agar (NA), Antibiotic Assay Medium (AAM), Dextrose Tryptone Agar (DTA) and Tryptic Soy Agar (TSA) with Ca^{2+ added to a final concentration of 100 p.p.m. were used as recovery media. No significant differences were seen between D-values obtained except in the case of strain 12980 when comparing TSA with the other media and for strain 7953 comparing AAM and DTA. The optimum incubation temperature was slightly lower for heated than for unheated spores of} each strain, although, in general, 50 °C was adequate. Higher D-values were obtained at 50–55 °C. The effects of the pH of the medium in the range 5.0–7.0 and the addition of starch and phosphate on heat resistance have also been investigated. Maximum colony counts of heated spores were obtained at pH 7.0 and decreased as pH fell. D-values were significantly lower at pH ≤ 5.5. Increasing the concentration of phosphate in the recovery medium from 0 to 0.2% resulted in a progressive decrease in spore recovery and D-values. The addition of starch improved recoverability. The z-values obtained for the four strains studied under the different recovery conditions were similar with a mean value of 7.58 °C ± 0.28.     

High apparent ileal digestibility of amino acids in raw and germinated faba bean (Vicia faba)‐ and chickpea (Cicer arietinum)‐based diets for rats

The effects of germinated faba bean (Vicia faba minor var Alameda)‐ and chickpea (Cicer arietinum kabuli var Athenas)‐based diets on performance, N utilisation, amino acid ileal digestibility and plasma concentrations were studied in growing male Wistar rats. Raw and germinated faba bean and chickpea seed meals were incorporated in essential amino acid‐supplemented and energy‐equalised diets as the only sources of protein. A lactalbumin‐based diet equalised in protein (100 g kg^?1) and digestible energy (15.5 kJ g^?1) with the test diets was used as control. Weight gains, gain/feed ratios, N retention and NPU values of animals fed raw or germinated legumes were lower than those of rats given the control (lactalbumin) diet, while faecal dry weights were higher. However, N retention and NPU values of rats fed germinated faba bean diets were higher and faecal dry weights lower than those of animals fed non‐germinated faba bean diets. Liver and thymus fresh and dry relative weights were lower than controls for all legume diets, whilst small intestine, caecum and colon relative weights were higher than controls for non‐germinated faba beans and chickpeas either germinated or not. Caecum and colon fresh and dry relative weights of rats fed germinated faba bean seeds were lower than those of rats fed non‐germinated faba beans and not different from controls. Except for aspartic acid and proline in rats fed raw faba bean diets, apparent ileal digestibilities of amino acids were not different or higher in rats fed legume diets as compared with controls. Except for arginine, apparent ileal amino acid digestibility was higher for germinated than for non‐germinated faba bean seeds. The amounts of glycine, arginine and ornithine in plasma significantly increased whilst those of threonine, alanine, leucine and lysine decreased with respect to controls in faba bean‐ or chickpea‐fed rats, either germinated or not. We conclude that (a) germination of faba bean seeds gave rise to a significant (P < 0.01) but limited improvement in performance, N retention and apparent ileal digestibilities of some amino acids in growing rats compared with non‐germinated seeds, while there was no detectable effect in the case of germinated chickpea seeds, and (b) the apparent ileal amino acid digestibility of essential amino acid‐supplemented diets based on faba bean or chickpea meals, either germinated or not, is similar or even higher than controls. © 2002 Society of Chemical Industry     

Retention of arsenic and selenium compounds using limestone in a coal gasification flue gas

Volatile arsenic and selenium compounds present in coals may cause environmental problems during coal combustion and gasification. A possible way to avoid such problems may be the use of solid sorbents capable of retaining these elements from flue gases in gas cleaning systems. Lime and limestone are materials that are extensively employed for the capture of sulfur during coal processing. Moreover, they have also proven to have good retention characteristics for arsenic and selenium during combustion. The aim of this work was to ascertain whether this sorbent is also useful for retaining arsenic and selenium species in gases produced in coal gasification. The study was carried out in a laboratory-scale reactor in which the sorbent was employed as a fixed bed, using synthetic gas mixtures. In these conditions, retention capacities for arsenic may reach 17 mg g(-1) in a gasification atmosphere free of H2S, whereas the presence of H2S implies a significant decrease in arsenic retention. In the case of selenium, H2S does not influence retention which may reach 65 mg g(-1). Post-retention sorbent characterization, thermal stability, and water solubility tests have shown that chemical reaction is one of the mechanisms responsible for the capture of arsenic and selenium, with Ca(AsO2)2 and CaSe being the main compounds formed.     

Influence of Natural Crosslinkers on Chitosan Hydrogels for Potential Biomedical Applications

Chitosan (CH) is a very well-known biopolymer that has been widely used for the development of biomaterials with a wide range of applications in the biomedical field, such as the preparation of hydrogels, owing to its outstanding anti-inflammatory, antibacterial and antifungal properties, biocompatibility and biodegradability, although they present limited mechanical properties. Chemical crosslinking is one of the most recurrent strategies for the reinforcement of these structures and, above all, crosslinking with natural-origin compounds that do not compromise their biocompatibility is considered a hot topic in this research field. D-fructose (F), obtained from the hydrolyzation and further isomerization of starch, an abundant raw material and genipin (G), which is extracted from the fruits of Gardenia jasminoides Ellis are used as natural crosslinkers. Chitosan-based hydrogels crosslinked with each crosslinking agent are prepared and characterized through Fourier transform infrared (FTIR) spectroscopy, crosslinking and swelling degree determination, rheological, microstructural, and biological studies. The results demonstrate that crosslinking with G is more beneficial for chitosan-based hydrogels since these samples showed more compact structures and better rheological performance. Additionally, excellent biological in vitro behavior due to the crosslinking with G, unlike that of F.     

Cytosolic 5′-Nucleotidase II Silencing in Lung Tumor Cells Regulates Metabolism through Activation of the p53/AMPK Signaling Pathway

Cytosolic 5′-nucleotidase II (cN-II) is an allosteric catabolic enzyme that hydrolyzes IMP, GMP, and AMP. The enzyme can assume at least two different structures, being the more active conformation stabilized by ATP and the less active by inorganic phosphate. Therefore, the variation in ATP concentration can control both structure and activity of cN-II. In this paper, using a capillary electrophoresis technique, we demonstrated that a partial silencing of cN-II in a pulmonary carcinoma cell line (NCI-H292) is accompanied by a decrease in adenylate pool, without affecting the energy charge. We also found that cN-II silencing decreased proliferation and increased oxidative metabolism, as indicated by the decreased production of lactate. These effects, as demonstrated by Western blotting, appear to be mediated by both p53 and AMP-activated protein kinase, as most of them are prevented by pifithrin-α, a known p53 inhibitor. These results are in line with our previous observations of a shift towards a more oxidative and less proliferative phenotype of tumoral cells with a low expression of cN-II, thus supporting the search for specific inhibitors of this enzyme as a therapeutic tool for the treatment of tumors.     

Vascular effects of egg white‐derived peptides in resistance arteries from rats. Structure–activity relationships

BACKGROUND: The vasodilator properties of several peptide sequences derived from egg white proteins were screened in mesenteric resistance arteries from Wistar‐Kyoto rats. For this, third‐order branches of the mesenteric arteries from 6‐month‐old male rats were used. The vasodilator responses, with or without endothelium, to several peptides (0.1 mmol L^?1) were analysed in an isometric myograph. Moreover, the effect of nitric oxide (NO) synthase (L‐NAME, 100 µmol L^?1) and cyclooxygenase (indomethacin, 10 µmol L^?1) inhibitors on the vasodilator response was tested. RESULTS: The peptides Arg‐Ala‐Asp‐His‐Pro‐Phe‐Leu, Arg‐Ala‐Asp‐His‐Pro‐Phe, Arg‐Ala‐Asp‐His‐Pro, Tyr‐Arg‐Gly‐Gly‐Leu‐Glu‐Pro‐Ile‐Asn‐Phe, Arg‐Asp‐Ile‐Leu‐Asn‐Gln and Val‐Pro‐Pro showed a high endothelium‐dependent vasorelaxation, whereas Phe‐Arg‐Ala‐Asp‐His‐Pro‐Phe‐Leu was only partially endothelium‐dependent. The relaxation induced by Arg‐Ala‐Asp‐His‐Pro‐Phe‐Leu, Arg‐Ala‐Asp‐His‐Pro‐Phe, Arg‐Ala‐Asp‐His‐Pro, Arg‐Asp‐Ile‐Leu‐Asn‐Gln and Val‐Pro‐Pro was mainly mediated by NO, since the response was inhibited only by L‐NAME, while both L‐NAME and indomethacin inhibited the vasodilator response induced by Phe‐Arg‐Ala‐Asp‐His‐Pro‐Phe‐Leu and Tyr‐Arg‐Gly‐Gly‐Leu‐Glu‐Pro‐Ile‐Asn‐Phe. The presence of Arg or Tyr at the N‐terminal position could be related to the vasodilator activity of these compounds in this vascular bed. The well‐known angiotensin‐converting enzyme inhibitor captopril showed only a slight vasodilator effect. CONCLUSION: These peptides could reduce the vascular resistance and be used as functional ingredients in the prevention and/or treatment of hypertension and other associated disorders. Copyright © 2010 Society of Chemical Industry