Chemical and microstructural evaluation of ‘hard‐to‐cook’ phenomenon in legumes (pinto bean and small‐type lentil)

Some physicochemical and microstructural characteristics of hard‐to‐cook (HTC) and easy‐to‐cook (ETC) pinto beans and small‐type lentils were compared. The development of HTC seeds was monitored over 6 months for changes in physicochemical properties. Results indicated that hardness, extent of water absorption and solid loss of HTC legumes were, respectively, 21–97%, 7–72% and 62–236% higher than those of ETC legumes. In addition, darkening of HTC beans and lentils was significantly higher than those of ETC ones. Scanning electron microscope observations indicated deteriorations in cytoplasmic contents of cotyledon cells of hard seeds. Phytic acid and total phenolic contents were, respectively, decreased 36–61% and 43–61% during storage, whereas hardness of seeds was increased 3–6 times. The soaking of hard seeds in sodium solutions resulted in the improvement in legume texture.     

Effect of malt pretreatment on phytate and tannin level of two sorghum (Sorghum bicolor) cultivars

The seeds of two cultivars of Sudanese sorghum (Sorghum bicolor), namely Wad Ahmed and Tabat, were germinated for 4 days to obtain 1‐, 2‐ and 4‐day‐old malts. Sorghum malt (5% and 10%) was added to sorghum flour. The mixtures were incubated at 30 °C with shaking for 30, 60, 90 and 120 min. Malting loss was very slight for both cultivars and for all incubation periods. Phytic acid and tannin contents were assayed for all treatments. The results revealed that phytate and tannin contents were significantly (P ≤ 0.05) reduced when sorghum flour was pretreated with malt. When a mixture containing 10%, 4‐day‐old malt and sorghum flour was incubated for 120 min, it significantly (P ≤ 0.05) reduced phytate and tannin contents by 92% and 98%, respectively, for Wad Ahmed cultivar, while for Tabat they were reduced by 93% and 96%, respectively. The rate of reduction of phytate and tannin content increased with incubation time and malt age and concentration.     

The effect of germination on the phytase activity,phytate and total phosphorus contents of some Nigerian‐grown grain legumes

BACKGROUND: Grain legumes are under‐exploited as possible sources of phytase for the poultry industry. The current study was conducted to assess the effect of germination on phytase activities, phytate and total phosphorus content in samples of Nigerian‐grown grain legumes. The legumes screened were African yambean (AYB, Sphenostylis stenocarpa), lima bean (Phaseolus lunatus), pigeon pea (Cajanus cajan), cowpea (Vigna unguiculata) and groundnut (Arachis hypogea). RESULTS: Phytase activity was low in AYB, lima bean and pigeon pea but high in cowpea and groundnut. Phytate content ranged between 3.01 g kg^?1 and 8.95 g kg^?1 while total phosphorus content ranged between 2.63 g kg^?1 and 5.93 g kg^?1. The grain legumes with higher phytase activity recorded the lowest phytate and phosphorus content. During germination there was an initial 4‐fold to 35‐fold increase in phytase activity after 6–7 days of germination followed by a decrease until 10 days (P < 0.05). The increase in phytase activity during germination was accompanied by a significant reduction in phytate (P < 0.05) and a small but significant increase in total phosphorus. CONCLUSION: The increase in phytase activity and the accompanying decrease in phytate content could have a positive implication for the nutrition of poultry and ruminants and for the environment. Copyright © 2010 Society of Chemical Industry     

Composition of two Spanish common dry beans (Phaseolus vulgaris), ‘Almonga’ and ‘Curruquilla’, and their postprandial effect in type 2 diabetics

BACKGROUND: Legume consumption has been associated with a lower risk of developing type 2 diabetes. However, the type of legume is a modifier of its effect. Two Spanish dry bean varieties—white (‘Almonga’) and cream (‘Curruquilla’)—were analyzed and used in a postprandial study in type 2 diabetics to assess glucose, insulin and triacylglycerol in blood. RESULTS: ‘Curruquilla’ variety had higher total galactoside (stachyose, mainly), trypsin inhibitors and lectin content than ‘Almonga’. The canning liquid was discarded prior to the analysis and the bean consumption by the subjects. The canning process reduced the total α‐galactoside content (>50%), practically eliminated trypsin inhibitors, and no lectin content was found. After bean consumption, maximum glucose was obtained at 60 min and was three times lower than that in bread. After bean intake, maximum insulin was produced 60 min with ‘Almonga’ and occurred later (90 min) with ‘Curruquilla’ and bread. After ‘Almonga’ intake, the area under the curve response of triglycerides was 14% lower compared to bread (P = 0.013). CONCLUSIONS: ‘Almonga’ and ‘Curruquilla’ are similar in the content of the nutritional but not in that of the antinutritional components. Both beans showed similar effects on blood glucose and insulin in type 2 diabetics and marked differences compared to those of bread in terms of magnitude and time course, but only ‘Almonga’ rendered a significant reduction in the triglyceridemic response. © 2012 Society of Chemical Industry     

Chilling injury development of ‘Tahitian’ lime, ‘Emperor’ mandarin, ‘Marsh’ grapefruit and ‘Valencia’ orange

The effect of varying levels of ethylene on the chilling injury (CI) development and the changes in the levels of putrescine, squalene and α-farnesene of ‘Tahitian’ lime (Citrus latifolia Tanaka), ‘Emperor’ mandarin (Citrus reticulata Blanco), ‘Marsh’ grapefruit (Citrus paradisi Macf) and ‘Valencia’ orange (Citrus sinensis L Osbeck) stored at 0°C was investigated. It was found that different citrus fruits stored at 0°C had varying sensitivity to CI, and that low levels of exogenous ethyiene induced earlier and more severe CI in all citrus fiuits. The levels of endogenous putrescine, squalene and α-farnesene varied between fruit, and was affected by the time of exposure at 0°C and the presence of ethylene. The patterns of change indicate that loss of squalene coupled with loss of α-farnesene could be involved in induction of CI.     

Effect of dietary mineral phosphorus and phytate on in situ ruminal phytate disappearance from different concentrates in dairy cows

The first objective of this study was to determine the influence of dietary composition on the in situ disappearance of phytate (InsP₆) from wheat, corn, soybean meal, and rapeseed meal [solvent-extracted, without (RSM) or with (hRSM) heat treatment] in the rumen of dairy cows. The second objective was to assess the primary degradation products of InsP₆ in the rumen. Three diets differing in phosphorus and InsP₆ concentration (basal diet = 0.38% P in dry matter; high-P diet = 0.56% P; high-InsP₆ diet = 0.39% P) were fed to 3 ruminally fistulated lactating Jersey cows in a 3 × 3 Latin square. Ground concentrates (sieve size = 2 mm) were incubated in polyester bags in the rumen for 2, 4, 8, 16, and 24 h. The bag residues were analyzed for P, InsP₆, isomers of lower inositol phosphates (InsP₅, InsP₄, InsP₃), and crude protein. The InsP₆ disappeared more rapidly from cereal grains than from oilseed meals; however, after 24 h of incubation ≥95% InsP₆ had disappeared from all concentrates except hRSM (57%; diet average). Feeding the high-InsP₆ diet increased InsP₆ disappearance for oilseed meals, but not for corn and wheat. The predominant InsP₅ isomer in all bag residues was Ins(1,2,4,5,6)P₅ followed by Ins(1,2,3,4,5)P₅ and Ins(1,2,3,4,6)P₅. A further InsP₅ isomer [Ins(1,3,4,5,6)P₅] was detected in both rapeseed meal bag residues. Feeding the high-InsP₆ diet led to lower concentrations of Ins(1,2,4,5,6)P₅ and Ins(1,2,3,4,5)P₅, whereas an interaction between diet, concentrate, and time occurred for Ins(1,2,3,4,6)P₅ and Ins(1,3,4,5,6)P₅. The results confirm the high potential of rumen microorganisms to hydrolyze InsP₆; however, increasing the amount of InsP₆ in the diet can further enhance InsP₆ hydrolysis, which may be relevant when concentrates with slowly degradable InsP_6, such as RSM or heat-treated concentrates, are fed to dairy cows. Based on the concentrations of InsP₅ isomers, 3 and 6 phytases appear to play a major role in the rumen. Conversely, intrinsic plant phytase activity appears to be less relevant as the percentage of its primary hydrolysis product, Ins(1,2,3,4,5)P₅, changed only slightly upon using wheat known for high intrinsic phytase activity instead of the other concentrates. Additional information regarding the factors influencing the extent of ruminal InsP₆ disappearance will require further studies to determine the phytase activity of rumen microorganisms and the characteristics of their respective phytases.     

Effect of delayed storage and continuous ethylene exposure on flesh reddening of ‘Royal Diamond’ plums

BACKGROUND: Flesh reddening has been described as one of the manifestations of plum fruits to low‐temperature storage for prolonged periods. The influence of factors such as ethylene and delayed storage has not been studied to date. In order to assess that, plum cv. ‘Royal Diamond’ fruits were (a) stored at 5 °C (control), (b) held at 20 °C for 2 days before storage at 5 °C (delayed storage) or (c) maintained at 5 °C under 15 µL L^?1 ethylene. Fruits were then transferred to 20 °C and ethylene, respiration, weight loss, firmness, soluble solids content, acidity, flesh reddening, anthocyanin accumulation and phenylalanine ammonia‐lyase (PAL) activity were determined. RESULTS: Delayed storage fruits showed more extensive flesh reddening than control fruits, with increased PAL activity and higher anthocyanin accumulation. Symptoms were expressed more markedly when fruits were stored at 5 °C in ethylene. CONCLUSION: Results indicated that the fruit ripening stage is a critical factor determining the susceptibility of ‘Royal Diamond’ plums to flesh reddening. Fruits continuously exposed to ethylene showed a dramatic increase in reddening, suggesting that ethylene contributes to the development of the disorder. Copyright © 2008 Society of Chemical Industry     

Quality aspects of fresh‐cut ‘long‐storage tomato’ as affected by package,calcium chloride and storage time

In this research, some quality changes during storage at 4 °C were assessed in fresh‐cut fruits of a ‘long‐storage tomato’ landrace, packaged in biocompostable materials (PLA Ingeo tray/NatureFlex? film) or in conventional plastics (PET tray + polypropylene film). The effects of dipping in CaCl₂ on the shelf‐life extension were also assessed. Plants were cultivated both off‐season (greenhouse) and in‐season (open field). CO₂ and O₂ concentration, fruit weight loss, firmness, colour, microbial load were measured at 0, 4, 7, 12 days of storage. Headspace gas changes and fruit weight loss were minimised in conventional package. BIO package prevented water condensation, led to max 5% weight loss and made fruits less susceptible to spoilage. Dipping in CaCl₂ induced better firmness, especially in biopackage. Off‐season fruits had overall lower quality than in‐season fruits; however, these may contribute to extend the production season, with interesting marketing implications for the agri‐food industry.     

Effect of the side chain size of 1‐alkyl‐pyrroles on antioxidant activity and ‘Laba’ garlic greening

Previous studies showed that 1‐alkyl‐pyrroles not only occur in fresh food products postulated as a natural antioxidant but also might be involved in garlic greening. In the present study, a series of 1‐alkyl‐pyrroles with different side chain size were synthesised to study the relationship of structure and antioxidative activity and their effects on ‘Laba’ garlic greening. The antioxidative activity of these compounds was evaluated by the method of scavenging ABTS˙ and DPPH˙. Results showed that increasing the size of R groups on the side chain, the antioxidative activity decreased gradually against the two radicals. The 1‐alkyl‐pyrroles generally exhibited stronger scavenging activities against ABTS˙ than DPPH˙. In contrast, their corresponding amino acids except for tyrosine showed almost no antioxidative activities while pyrrole exhibited much weaker activity as compared with the 1‐alkyl‐pyrroles, suggesting that the 1‐alkyl‐pyrroles donate H‐atom from pyrrole moiety rather than side chain to quench the two radicals. On the other hand, all 1‐alkyl‐pyrroles can turn newly harvested garlic green but to a different extent. All these results suggested that these pyrrole derivatives occurring in foodstuff played an important role in either protecting foodstuff from oxidation or acting on pigment precursors during ‘Laba’ garlic greening.     

Amino acid profiles and protein quality of cooked cassava leaves or ‘saka‐saka’

Cassava (Manihot esculenta Crantz) leaves form the main source of protein in a diet consisting of processed cassava roots as sole staple food in konzo‐affected areas of the Democratic Republic of Congo. Pounded cassava leaves were hydrolysed and analysed by HPLC before and after cooking to assess amino acid profiles and protein quality. An average of about 58% loss of total protein content was observed in five different cooked samples. The protein content in cassava leaves was high, an average of 285.9 g kg^?1 dry weight in the raw and 119.2 g kg^?1 dry weight in the cooked samples, but of poor quality, with sulphur amino acids as the most limiting amino acids. Lysine and leucine were also limiting amino acids in some of the raw samples. Lysine, histidine, leucine and isoleucine were limiting amino acids in the cooked samples besides the sulphur amino acids. The consumption of cassava leaves does not compensate the dietary deficiency of sulphur amino acids in the roots that are the staple food in konzo‐affected areas. Sulphur amino acids are essential for detoxification of the residual cyanogens remaining in insufficiently processed cassava roots. Cereals and legumes, as sources of sulphur amino acids and lysine respectively, should be promoted as part of the diet in those areas to prevent the paralytic neuro‐toxico‐nutritional disease konzo among the poor population. Copyright © 2003 Society of Chemical Industry     

Interaction of phytate with protein and minerals in a soybean–maize meal blend depends on pH and calcium addition

In order to investigate possible interactions of phytate with protein and minerals in simplified animal diets, studies were conducted on the solubility of endogenous phytate, protein and essential minerals in a soybean–maize meal blend within a physiological relevant pH range. The blend was mixed with water for 10 min and then allowed to incubate at 40 °C (30 min) after adjustment of the pH. Finally, soluble phytate, protein, zinc, manganese and iron were determined. Phytate and mineral solubility was highly influenced by pH whereas protein solubility was less affected. Addition of 5 g Ca²⁺ kg^?1 drastically reduced the solubility of phytate, zinc, manganese and iron at pH above 4.4, indicating that the formation of insoluble phytate–mineral complexes is increased in the presence of calcium. The action of pepsin increased the solubility of protein and phytate at pH below 4, indicating that insoluble phytate–protein complexes are present at low pH. Calcium had the same solubilising effect as pepsin at pH 2–4 but to a lesser degree. Copyright © 2007 Society of Chemical Industry     

Effect of grain source and exogenous phytase on phosphorus digestibility in dairy cows

Two experiments were conducted to determine P digestibility in lactating dairy cows fed corn or barley as grain sources. The first experiment utilized a replicated incomplete 5 × 4 Latin square design with 8 lactating Holstein cows fed diets containing either corn alone or corn in combination with one of 4 barley varieties that differed in chemical composition. Total tract digestibility of P ranged from 11 to 29% for diets containing the barley varieties and was approximately 35% for the corn diet. A second experiment compared P digestibility in cows fed diets containing corn or barley when exogenous phytase was added to the diets. Lactating Holstein cows (n = 16) were arranged in 4 replications of a Latin square with 2 grains (barley or corn), fed separately or with added exogenous phytase (427 phytase units/kg of total mixed ration and 4 periods of 21 d. Phytate P comprised about 50% of the total P (0.46% P) in the total mixed ration. The concentration of serum inorganic P was higher in cows fed diets with exogenous phytase (5.8 vs. 6.5 mg/dL in cows fed barley diets and 5.5 vs 6.0 mg/dL in cows fed corn diets). Using acid detergent lignin as an internal marker, hydrolysis of phytate P was increased by the exogenous phytase, and total P digestibility tended to be increased. In contrast to Experiment 1, in Experiment 2 there was no effect of grain source on P digestibility and total fecal P. Dry matter intake and efficiency of milk production were not affected by exogenous phytase or grain type. Although phytase activity occurs in the rumen, physical properties of the diet and ruminal passage rates may prevent total hydrolysis of phytate in the rumen of lactating cows. Thus, exogenous dietary phytase might improve P digestibility in dairy cows in some dietary situations.     

Effect of nano‐ZnO‐coated active packaging on quality of fresh‐cut ‘Fuji’ apple

A novel nanopackaging was synthesised by coating polyvinyl chloride (PVC) film with nano‐ZnO powder, and its effects on the preservation quality of fresh‐cut ‘Fuji’ apple were investigated at 4 °C for 12 days. Compared with the control (PVC film), nanopackaging significantly reduced the fruit decay rate (P < 0.05), as well as decreased the accumulation of malondialdehyde (MDA) from 74.9 nmol g^?1 in the control to 53.9 nmol g^?1 in the nanopackaging. Cutting caused an increase in ethylene level, suggesting wound‐induced ethylene production, which was suppressed in nanopackaging. Both the polyphenoloxidase and pyrogallol peroxidase activities were decreased in nanopackaging fruit. The initial appearance of apple slices was retained, and the browning index was prevented in nanopackaging samples, which was only 23.9, much lower than the control of 31.7 on day 12. These results indicated that nano‐ZnO active packaging could be a viable alternative to common technologies for improving the shelf‐life properties of ‘Fuji’ apples as a fresh‐cut product.     

植酸酶对鲫鱼养殖中磷、粗蛋白质和粗脂肪的影响

通过设置5组不同水平无机磷和植酸酶添加量的饲料来喂养鲫鱼,探索鲫鱼饲料中植酸酶和无机磷之间的最佳配比。结果表明:用植酸酶替代无机磷能明显减少养殖水体中磷的排放,同时能满足鱼体对磷的需求,对鱼体粗蛋白质含量影响较小,并能降低鱼体粗脂肪的含量。最佳的无机磷盐和植酸酶配比是1 kg饲料中加9 g的Ca(H2PO4)2和1500 U的植酸酶,其磷的排放量减少了66.9%,粗脂肪含量降低17.65%。     

(+)‐Catechin and (−)‐epicatechin levels of concentrated and ready‐to‐drink grape juices through storage

Commercial concentrated Concord (CCJ) and Isabel (CIJ) grapes juices were stored at 4–5 °C while pasteurised ready‐to‐drink juices of the same grape cultivars (PCJ and PIJ) were kept at 20–25 °C under indirect light for 10 months, simulating industrial storage conditions. (+)‐catechin preservation during storage ranged between 63% (PCJ) and 52% (PIJ); (?)‐epicatechin retention was of 32% (CCJ) and 15% (CIJ). Total phenols retention ranged from 93% (CCJ) to 84% (PCJ) and radical scavenging activity (RSA) from 87% (PIJ) to 85% (CCJ and PCJ). Concentrated juices showed higher monomeric flavan‐3‐ols amounts and CCJ depicted superior phenolic contents. PIJ yielded the highest RSA during storage per phenolic unit. Process and storage impacted flavan‐3‐ols and not total phenolics and RSA during 10‐month ageing.