Water uptake and its impact on the texture of lentils (Lens culinaris)

Water uptake behavior of three cultivars of lentils (Boomer, French-green and Nugget) was studied at three different hydration temperature regimes (room temperature, 50 °C and 85 °C). Boomer had the highest amount of water uptake capacity (74.60 g water/100 g of seeds) at room temperature (20 °C) which can be linked with its pore properties. French-green lentils imbibed the largest amount of water at elevated soaking temperatures (50 °C and 85 °C) and can be attributed to its higher seed surface area to volume ratio, high protein content and relatively thinner seed coat. Water uptake at elevated temperatures (50 °C and 85 °C) were predicted by a two parameter Mitscherlich model (R² > 0.99, χ² < 0.5) within 1.36–3.07% average absolute error. At room temperature, only the water uptake of Boomer was reasonably predicted by this model. The texture (hardness) of the soaked lentils was found to be related the amount of water uptake and soaking temperature used rather than seed size or seed mass alone. The hardness values of Boomer, French-green and Nugget at 85 °C after 75 min soaking were reduced to 5.66%, 3.53% and 6.77%, respectively compared to their respective initial seed hardness values. The water uptake capacity of the aged Boomer was found to be significantly reduced compared to the fresh seeds (p < 0.01) while French-green and Nugget do not exhibit significant change (p < 0.05). During 72 h of germination, hardness of all lentil cultivars showed a typical pattern which decreased in the first 24 h followed by an increase compared to the hydrated seeds. A peak hardness value was obtained within 36–48 h before finally declining in all types of lentils. Structural changes within the cotyledon, such as depletion of starch granules, new nuclei formation and development of tissues in vascular bundles and rupture of the seed coat were observed during germination.     

Effects of variety and crude protein content on nutrients and anti-nutrients in lentils (Lens culinaris)

Protein content was used as an indicator of environmental conditions for a study on varietal and environmental variation of proximate composition, minerals, amino acids and anti-nutrients of lentils. Four lentil varieties, each with three levels of protein content, were selected. Crude protein content ranged from 24.3% to 30.2%. Analysis of variance showed that both varietal and environmental conditions had a significant effect on starch content. Significant varietal differences were found in acid detergent fibre (ADF), neutral detergent fibre (NDF), fat, ash, calcium (Ca), copper (Cu), potassium (K), manganese (Mn), phosphorus (P) and Zinc (Zn). Protein showed significant effects on the amino acids, arginine and tryptophan. Variety had a significant effect on sucrose, stachyose, phytic acid, tannins and trypsin inhibitor activity (TIA). Major lentil components, protein and starch content were inversely correlated. K, Mn, P and Zn were negatively correlated with protein content. Tryptophan was the most deficient amino acid and the sulphur-containing amino acids were the second limiting amino acid in lentils. Raffinose was positively correlated with starch while negatively correlated with ADF.     

Effect of variety and processing on nutrients and certain anti-nutrients in field peas (Pisum sativum)

The effect of variety and processing (soaking, cooking and dehulling) on nutrients and anti-nutrients in field peas (Pisum sativum) was investigated. Analysis of variance showed that variety had a significant effect on crude protein, starch, ash, soluble dietary fibre (SDF), insoluble dietary fibre (IDF), total dietary fibre (TDF), trypsin inhibitor activity (TIA), minerals, phytic acid, sucrose and oligosaccharides. Soaking and cooking increased protein content, IDF, TDF, Ca, Cu, Mn and P in peas whereas ash content, Fe, K, Mg, Zn, sucrose and oligosaccharides were reduced. TIA was increased by soaking but reduced by cooking. Cooking was more effective than soaking in reducing oligosaccharides. Dehulling increased crude protein, starch, K, P, phytic acid, stachyose and verbascose content but reduced SDF, IDF, TDF, Ca, Cu, Fe, Mg and Mn.     

Influence of germination on the nutritional quality of Phaseolus vulgaris and Cajanus cajan

Germination is a method that can modify the presence of nutrients and antinutrients in legume seeds. In this study, the changes in trypsin inhibitors activity (TIA), phytic acid, tannins, ascorbic acid, thiamine, protein digestibility and minerals in germinated black beans (Phaseolus vulgaris L.), white beans (Phaseolus vulgaris L.) and pigeon beans (Cajanus cajan L. Millsp) were evaluated. The ungerminated grains were analysed as control. A significant decrease in the content of TIA of pigeon beans (19.2%), white beans (52.5%) and black beans (25%) was observed. The reduction of phytic acid was more than 40% for the three grains germinated; for the tannins, the reduction was of 14.3% for pigeon beans, 19% for black beans and 36.2% for white beans. Germination increased the protein digestibility in a 2-4% range, and also increased the ascorbic acid by 300% for white beans, by 33% for black beans and by 208% for pigeon beans. The thiamine content increased more than 26.7%. Germination affected the mineral content erratically, depending more on the grain and the type of mineral. These variations in the content of nutrients and antinutrients of the germinated grains are attributed to the joint effect of the germination and previous soaking the grains were subjected to.     

The effect of several cooking treatments on subsequent chilled storage of thawed deepwater pink shrimp (Parapenaeus longirostris) treated with different melanosis-inhibiting formulas

This work deals with the effect that different cooking methods have on quality of shrimps (Parapenaeus longirostris) during the chilled storage. Vacuum-cooking (sous-vide) and steaming were compared with the traditional cooking process in boiling water. The effect of prior treatment with several melanosis-inhibiting agents (with a commercial sulphite- or 4-hexylresorcinol-based formula) was also tested. Neither the melanosis-inhibiting blends nor the cooking methods used significantly affected the water-holding capacity, firmness or moisture content of the cooked shrimps. Spraying with a 4-hexylresorcinol-based formula was effective in preventing microbial growth during storage. Vacuum-cooking was also shown to be the most effective way of preventing microbial growth although the TVB-N content of cooked shrimps increased significantly. By discriminant analysis, a combination of prior spraying with 4-hexylresorcinol-based formula followed by vacuum-cooking, proved to be the best method for obtaining shrimps with a very good appearance and high microbial quality. The foregoing may be very important for the cooking industries.     

Content of antinutritional factors and HCl-extractability of minerals from white bean (Phaseolus vulgaris) cultivars: Influence of soaking and/or cooking

White bean seeds were subjected to soaking in distilled water for 1, 2 and 3 days. In order to perform complete processing, the seeds were cooked until soft. Effects of soaking and/or cooking of white bean seeds on antinutritional factors, mineral contents and HCl-extractability were studied. Phytic acid and polyphenol contents of all cultivars were reduced. Soaking alone and soaking, followed by cooking, reduced mineral contents of the cultivars, but HCl-extractability was significantly (P ? 0.01) improved to varying extents, depending on cultivar type. Soaking and/or cooking treatment was thus found to be an effective technique and caused further improvement in the availability of both major and trace minerals in white bean.     

Effect of cultivar and environment on physicochemical and cooking characteristics of field pea (Pisum sativum)

The effects of cultivar, growing location and year on physicochemical and cooking characteristics of field pea (Pisum sativum) were investigated and the relationship between these characteristics was determined. Six diverse field pea cultivars were grown in five different growing locations for two subsequent years (2006 and 2007). Cultivar, location and year had a significant effect on the seed weight, seed size, water hydration capacity, cooking time and firmness of cooked peas. Significant cultivar and location differences in protein, starch, crude fibre, fat, ash and phytic acid contents of peas were observed. Most of the traits were significantly affected by the interactions: cultivar-by-location, cultivar-by-year and location-by-year. Both seed weight and seed size were negatively correlated with crude protein and crude fibre contents. Cooking time was negatively correlated with crude fibre, ash and phytic acid contents, but positively correlated with firmness and starch content. A significant positive correlation was observed between ash content and phytic acid level in peas.     

Effect of the cooking on physicochemical and starch digestibility properties of two varieties of common bean (Phaseolus vulgaris L.) grown under different water regimes

Growing and cooking conditions influence the quality and nutritional value of beans. The objective of this research was to determine the effect of cooking on digestibility and physicochemical properties of two varieties of bean grown under different water regimes. Black 8025 and Pinto Durango varieties were grown in irrigated and temporal (rain fed) conditions in two locations of Guanajuato, Mexico. The pasting profiles of the cooked beans showed a significant decrease in viscosity. The enthalpy of the raw and cooked beans ranged from 2.75 to 3.95 and 0.62 to 0.97 J/g, respectively. The percentage of rapidly digestible starch and slowly digestible starch increased, while the percentage of resistant starch was lower in cooked samples. Black 8025 beans had lower glycemic index than Pinto Durango, but no significant difference (P < 0.05) was noted between water regimes. The variety of bean had a more pronounced effect on digestibility properties than the water regime.     

The effect of cooking on the fatty acid composition of longissimus muscle from beef heifers fed rations designed to increase the concentration of conjugated linoleic acid in tissue

Longissimus dorsi (LD) muscle from 60 Charolais crossbred heifers, aged for 14 days was used to investigate the effect of cooking on the content of PUFA and CLA fatty acids. Animals were offered a control diet of grass silage and concentrates (CO) or rations designed to enhance the concentration of CLA in tissue, i.e. unsupplemented grazed pasture (G), sunflower-oil supplemented grazing (SFG) or linseed-oil oil supplemented grazing (LSG). The SFG diet was the most effective for increasing the concentration of CLA but also caused the highest n-6/n-3 fatty acid ratio. There were no changes in the relative distribution of fatty acids upon cooking (140°C for 30min) and this procedure can be recommended because it preserves the nutritional value of the meat. It is concluded that irrespective of the change in the fatty acid composition of LD due to alteration in the diet of the cattle, cooking did not cause thermal degradation of PUFA, or thermal degradation or oxidative synthesis of CLA.     

Effect of cooking and sterilisation on the composition of amino acids in immature seeds of flageolet bean (Phaseolus vulgaris L.) cultivars

The aim of the work was to evaluate the amino acid content and protein quality in products of immature bean seeds with a dry matter content of 40%. The investigation included raw seeds, fresh seeds after cooking to consumption consistency and seeds after canning. Raw seeds of the cultivar Alamo contained more amino acids in 100 g fresh matter than the seeds of the cultivars Flaforte and Mona. Cooking and sterilisation brought about decreases in the content of all the amino acids in the investigated cultivars; 1–50% and 9–60% respectively. Higher losses being noted in sterilised seeds. If the results were expressed in 16 g N, the differences in amino acid content were much smaller. The amino acid content of Mona was lower than that of the remaining cultivars. The cooking of seeds did not bring about changes in relation to the raw material (except tyrosine which showed a decrease 35–45%); however, sterilisation affected the content of most amino acids (from −45 to +17%). Compared with the standard (FAO/WHO/UNU, 2007), the limiting amino acid was cystine with methionine (amino acid score 70–83). Of the seeds prepared for consumption, sterilised bean seeds had a higher EAA index value, while of the cultivars, the seeds of Alamo had the highest value (147–162).     

Effect of cooking on the chemical composition of lentils,rice and their blend (Koshary)

Lentils, rice and their blend (Koshary) were cooked by traditional Egyptian methods. Cooking resulted in slight changes in the total nitrogen, as well as in the non-protein nitrogen (NPN), ether extract and crude fibre of the three products, compared with raw grains. In contrast, significant decreases were found in the mineral elements, indicating losses through leaching, on washing and cooking. The mineral composition of lentils' cooking liquor confirmed this.     

Effect of cooking method on water absorption and ease of dehulling in preparation of African locust beans for Iru

Gas boiling or pressure cooking increased the level of water uptake by locust beans over that with firewood cooking, mainly because of sustained heat input. Presoaking in cold water produced no advantage. The boiling times necessary for satisfactory dehulling were 10h using firewood, 6h by gas boiling, and 30 and 50min respectively by pressure cooking at 121 and 115°C.     

Influence of germination techniques on sprout yield,biosynthesis of ascorbic acid and cooking ability,in chickpea (Cicer arietinum L.)

Effects of germination time and illuminations on sprout yield, biosynthesis of ascorbic acid, cooking ability and moisture accumulation in chickpeas were significant (p ? 0.01). Green light had the highest promoting effect on the ascorbic acid level (40.59 mg/100 g) as compared to other illuminations but significantly reduced the sprout yield (188.6 g) as compared to dark, fluorescence and γ-rays illuminations with significantly high sprout yield (196 g) and imbibing moisture (51%). Cooking time was reduced by 43% due to γ-rays in un-soaked seed. Cooking time increased in all treated chickpea samples after 24 h germination and thereafter decreased significantly. Red light significantly increased the cooking time (68.44 min) followed by fluorescent (64.5 min), yellow (61.8 min) and green light (60.9 min). The results indicated that germination of chickpea under green light was an effective process in enhancing ascorbic acid content while dark, fluorescence and γ-rays were effective in promoting sprout growth and to some extent biosynthesis of ascorbic acid.     

Effect of cooking conditions on the flavour compounds and composition of shrimp (Parapenaeus longirostris) broth

 To achieve a shrimp broth with the best flavour, the whole shrimp must be cooked at 85°C for 30 min in a 0.5% NaCl solution in proportions 1 : 2 (w : v). Quantitatively, the main components of the broth were nitrogen substances, the most abundant of these being peptides of molecular weight less than 600 Da. Levels of ATP metabolites were also determined [the more abundant compounds were inosine, guanosine 5′-monophosphate (GMP) and inosine 5′-monophosphate (IMP)], as were free sugars (glucose, fructose and ribose) and fat content. The free amino acid composition was also determined. A significant correlation (P <0.0001) between cooking temperature and different nitrogen fractions was observed. Received: 22 September 1997 / Revised version: 13 November 1997     

An influence of cooking on fatty acid composition in three varieties of common beans and in lentil

The fatty acid composition of three raw and cooked freeze-dried common bean varieties (Phaseolus vulgaris), namely enjevec, Semenarna 22 and Cipro, and of the lentil (Lens esculenta), var. Anicia, was determined and the influence of storage on their composition was studied. Analyses of fatty acid composition were conducted by in situ transesterification and capillary column gas-liquid chromatography. In raw milled beans average values of about 16% saturated fatty acids (SAT), 6% monosaturated fatty acids (MUFA) and 78% polyunsaturated fatty acids (PUFA) were found. Somewhat different values of 15% of SAT, 25% MUFA and 60% PUFA were found in lentil. In cooked beans the content of all fatty acids was slightly decreased. In cooked lentil the decrease was almost 50%, but the ratios of SAT, MUFA and PUFA in both cases were practically the same. After two years of storage at 4 °C the fatty acid content in raw milled beans was unchanged, but altered in cooked ones. The amounts of linoleic (18:2, n-6) and -linolenic (18:3, n-3) acid decreased, but myristic (14:0), margaric (17:0) and arachidic (20:0) acids increased. It was found that freeze-dried cooked beans, prepared from raw seed beans, kept 2.5 years at 10 °C, have practically the same fatty acid composition as freeze-dried cooked beans 0.5 year after harvesting.     

Influence of maturation and cooking treatments on the nutritional value of bovine meats: Water losses and vitamin B12

The aim of the study was to determine the influence of maturation and of cooking processes on water losses and on the vitamin B12 content of meat. Three types of muscle (Longissimus lumborum, Longissimus thoracis and Triceps brachii) were sampled from a total of 16 animals, representative of animals raised for meat production in France. Three durations of maturation were compared: 1, 3 and 14 days. Different cooking processes were applied: Longissimus lumborum was deep-fat fried or roasted, Longissimus thoracis was pan fried or grilled and Triceps brachii was braised. The cooking yield averaged 55-56% for Triceps brachii, 73-77% for Longissimus lumborum and 85-87% for Longissimus thoracis. Vitamin B12 concentration in raw meat was significantly higher in Triceps brachii than in Longissimus lumborum and Longissimus thoracis (20.86, 11.53 and 9.21ng/g wet tissue, in the same respective order). When expressed on a wet weight basis, all concentrations were significantly increased by cooking. When expressed on a lipid-free dry basis, significant losses in vitamin B12 were measured only in the braised Triceps brachii (-25%) and in the deep-fat fried Longissimus lumborum (-5.5%) as a result of long duration and high temperature of cooking, respectively. Maturation did not affect the vitamin B12 content of meat, whether raw or cooked.