Reduction of α-galactoside content in red gram (Cajanus cajan L.) upon germination followed by heat treatment

BACKGROUND: Red gram (Cajanus cajan L.) is an important crop for human and animal nutrition. However, raffinose family oligosaccharides present in red gram seed hinder its consumption as it is not digested by normal human carbohydrases and is further fermented by intestinal microflora, which induces flatulence. In order to make the grain legume more amenable for human consumption, we have tried to shed some light on the effect of germination followed by heat treatment methods such as autoclaving, cooking and pressure cooking on the raffinose family of sugars. These techniques, however, are primary prerequisites before consumption of the gram. RESULTS: The percent removal of raffinose, stachyose and verbascose after germinating red gram seeds for 8 h followed by autoclaving was 65.6%, 58.9% and 65.3% respectively; and after cooking was 61.6%, 69.2% and 72.5%. Germinating for 16 h followed by autoclaving led to a mean decrease of 53.3% for raffinose, 60.3% for stachyose and 62.3% for verbascose. Germination of red gram seeds for 16 h followed by cooking led to a mean decrease of 71.7% for raffinose, 76.2% for stachyose and 74.0% for verbascose, respectively. The results for the percent removal of raffinose, stachyose and verbascose after germination of red gram seeds for 16 h followed by pressure cooking was 68.3%, 73.3% and 68.2% respectively. CONCLUSION: This study demonstrates that local methods of processing reduce raffinose family oligosaccharides in red gram. The technique of germinating the seeds for 16 h followed by autoclaving, cooking and pressure cooking for the reduction of raffinose family oligosaccharides is a promising solution to overcome flatulence and increase the overall acceptance of red gram among general populace. Copyright © 2011 Society of Chemical Industry     

Tempeh Prepared from Germinated Soybeans

The oligosaccharide (sucrose, raffinose and stachyose) and phytate contents of soybeans were reduced by 12–24 hr germination. The tempeh fermentation of the germinated soybeans caused a further decrease in oligosaccharide, phytate and fat contents. As a result of these decreases, the proportion of protein (% N × 6.25) in the tempeh solids rose. The soybean lectins were not affected by the germination process but were inactivated during the preparation of tempeh. The adjusted protein efficiency ratio for regular tempeh was 2.19 vs 2.26 for tempeh prepared from germinated soybeans. The difference, however, was not statistically significant (n = 10 rats).     

Effect of Soaking and Cooking on the Oligosaccharide Content of Dry Beans (Phaseolus vulgaris, L.)

The effect of cooking conditions commonly used in Brazilian homes was determined by measuring the oligosaccharide content (sucrose, raffinose and stachyose) of beans (Phaseolus vulgaris, L.) by thin-layer chromatography. Soaking in water caused a small decrease in the oligosaccharide content of the beans and the relative amount removed was not proportional to the solubility of the sugars in water. Cooking of the whole seeds led to a larger decrease in oligosaccharide content, especially when large amounts of water were used.     

Mechanisms of Docosahexaenoic and Eicosapentaenoic Acid Loss from Pacific Saury and Comparison of Their Retention Rates after Various Cooking Methods

The docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) contents of Pacific saury (Cololabis saira), a fatty fish and staple of the Japanese diet, have been reported to decrease after cooking. This study compared the DHA and EPA contents remaining in saury after grilling, pan‐frying or deep‐frying to center temperatures of 75, 85, or 95 °C, and examined physical loss, lipid oxidation, and thermal degradation as mechanisms of DHA and EPA loss. Temperature changes inside the saury were monitored using thermocouples, while DHA and EPA contents, oxygen radical absorbance capacity, and measurements of lipid oxidation (that is, carbonyl value and thiobarbituric acid value) were determined chemically. Visualization of temperature distribution inside fish samples during cooking revealed large differences in heat transfer among cooking methods. True retention rates in grilled (DHA: 84 ± 15%; EPA: 87 ± 14%) and pan‐fried samples (DHA: 85 ± 16%; EPA: 77 ± 17%) were significantly higher than deep‐fried samples (DHA: 58 ± 17%; EPA: 51 ± 18%), but were not affected by final center temperatures despite differences in cooking times. Physical loss via cooking losses (grilling and pan‐frying) or migration into frying oil (deep‐frying) accounted for large quantities of DHA and EPA loss, while lipid oxidation and thermal degradation did not appear to be major mechanisms of loss. The antioxidant capacity of saury was not significantly affected by cooking treatments. The results of this study suggest that minimization of physical losses during cooking may increase DHA and EPA contents retained in cooked Pacific saury.     

Changes in fatty acid,simple sugar,and oligosaccharide content of cowpea (Vigna unguiculata) flour as a result of soaking,boiling, and fermentation with Rhizopus microsporus var. oligosporus

Changes in fatty acid, simple sugar, and oligosaccharide content of cowpea flour as a result of soaking, boiling, and fermentation with Rhizopus microsporus var. oligosporus were investigated. The major fatty acids in flour made from both nonfermented and fermented cowpeas were linoleic, palmitic, and linolenic. With the exception of lower amounts of lauric, palmitic, linoleic, and linolenic acids and slightly higher amounts of lignoceric acid, the remaining fatty acids in flour made from soaked cowpeas were essentially unchanged from the control flour made from cowpeas that were not soaked, boiled or fermented. Soaking followed by boiling generally increased amounts of fatty acids in flour compared to the control. Rhizopus microsporus did not utilize lipid during 24 h of fermentation. Soaking decreased the amount of sucrose and stachyose by 39% and 18.4%, respectively, whereas soaking followed by boiling caused decreases of 58.3% and 49.3%. Complete elimination of sucrose, raffinose, and stachyose was achieved after 15 h of fermentation.     

Effect of soaking,germination, cooking and fermentation on antinutritional factors in cowpeas

The present work deals with the study of efficacy of some treatments, namely soaking (in water and bicarbonate solution( ordinary and pressure cooking, germination and fermentation in reducing or removal of antinutritional factors usually present in cowpeas (protease inhibitors, tannins, phytic acid and flatus‐producing oligosaccharides (raffinose and stachyose). The results showed that long‐time soaking (16 h) in bicarbonate solution caused remarkable reduction in the antinutritional factors. Pressure cooking was more effective than ordinary. Cooking pregerminated cowpeas was most effective. Fermentation completely removed trypsin inhibitor, oligosaccharides and reduced remarkably phytic acid. However, tannins noticeably increased.     

Effect of soaking,germination, cooking and fermentation on antinutritional factors in cowpeas

The present work deals with the study of efficacy of some treatments, namely soaking (in water and bicarbonate solution), ordinary and pressure cooking, germination and fermentation in reducing or removal of antinutritional factors usually present in cowpeas (protease inhibitors, tannins, phytic acid and flatus-producing oligosaccharides (raffinose and stachyose). The results showed that long-time soaking (16 h) in bicarbonate solution caused remarkable reduction in the antinutritional factors. Pressure cooking was more effective than ordinary. Cooking pregerminated cowpeas was most effective. Fermentation completely removed trypsin inhibitor, oligosaccharides and reduced remarkably phytic acid. However, tannins noticeably increased.     

Effect of soaking,cooking and crude α-galactosidase treatment on the oligosaccharide content of red gram flour

The contents of sucrose, raffinose, stachyose, verbascose, total soluble sugars and reducing sugars in whole seeds of 14 cultivars of red gram (Cajanus cajan) grown in Karnataka state were determined. The effects of soaking, cooking and crude α-galactosidase treatment on the levels of the raffinose family of sugars were investigated. The percent losses of raffinose, stachyose and verbascose after soaking the red gram seeds for 16 h were 54.6, 55.4 and 33.3%, respectively. Cooking the red gram seeds for 60 min resulted in a decrease of 80.2% for raffinose, 87.2% for stachyose and 81.6% for verbascose. Thin-layer chromatographic analyses of 4 h enzyme-treated samples revealed complete hydrolysis of galactooligosaccharides. Therefore, α-galactosidase from Cassia sericea could have potential use in the food industry.     

Fate of oligosaccharides during production of soya bean tempe

The concentrations of the flatulence and possibly prebiotic oligosaccharides, stachyose and raffinose, as well as sucrose, glucose and fructose, were monitored during the preparation of bacteria‐free tempe made with Rhizopus oligosporus NRRL 2710. The initial soya beans contained (g [kg dry matter]⁻¹): stachyose, 30; raffinose, 11; sucrose, 57, glucose, <0.1, and fructose, <0.1. Losses of oligosaccharides during preparation of tempe were due to leaching during the hydration (100°C for 30 min), washing (60°C) and cooking stages (121°C for 10 min). The losses were (g [kg dry initial soya bean]⁻¹): hydration 45; dehulling and washing, 14, and cooking, 24. Concentrations remaining in the cooked cotyledons were (g [kg dry weight]⁻¹): stachyose, 7.0; raffinose, 2.1; sucrose, 7.2; glucose, 1.8, and fructose, 0.9, representing 17% (w/w) of the stachyose, 15% of the raffinose and 13% of the sucrose+glucose+fructose in the initial soya beans. Within the errors of measurement, concentrations of stachyose, raffinose and sucrose did not change during the fermentation but concentrations of glucose and fructose were reduced to 0.2 and 0.3 g (kg dry weight)⁻¹, respectively. The results are discussed in relation to controlling the concentrations of oligosaccharides in tempe. © 1999 Society of Chemical Industry     

家庭烹调对鲟鱼中脂肪酸和胆固醇的影响

对杂交鲟鱼（Acipenser baerii×A. schrenckii）进行了清蒸、油煎、微波、微波烤、烤箱烤和压力锅煎6 种家庭烹调处理,测定其脂肪和胆固醇含量、脂肪氧化指标和各脂肪酸含量的变化。结果表明,所有烹调方法均降低了n-3/n-6多不饱和脂肪酸含量的比值,其中压力烹调比值最高（0.85）,清蒸次之（0.83）,而烤箱烤最低（0.73）。胆固醇保存率以清蒸和压力锅煎最高,两种处理间无显著差异。烹调后样品酸价和硫代巴比妥酸值上升而过氧化值下降,并与样品的胆固醇含量相关。清蒸和压力烹调中脂肪酸和胆固醇变化相对较少,可能与其密闭烹调条件造成氧化程度较低有关。     

Effect of Processing on Certain Antinutrients in Seeds of Şeker Variety (P. vulgaris L.) Grown in Turkey

Abstract

The effects of different cooking/autoclaving methods were investigated on sucrose, raffinose, stachyose, phytic acid, and tannins content of ?eker bean seeds (Phaseolus vulgaris). All these oligosaccharides and antinutrients decreased under various cooking/autoclaving treatments. Among the different cooking/ autoclaving treatments, 18 h sodium bicarbonate solution soaking followed by autoclaving procedures were the most effective for removing oligosaccharides (65–72%), phytic acid (51%), and tannins (100%). These conditions could be recommended to remove undesirable sugar contents and antinutrients of the ?eker bean used for culinary purposes.     

Effect of soaking,cooking and crude α-galactosidase treatment on the oligosaccharide content of cowpea flours

Abstract : The effects of soaking, cooking and crude α-galactosidase treatment on the level of stachyose and raffinose present in cowpea flours were investigated. Soaking for 16 h resulted in an average reduction of 26·2% for stachyose and 28·0% for raffinose, while cooking for 50 min resulted in a reduction of 28·6% for stachyose and 44·0% for raffinose. On the other hand, treatment of cowpea flours for 2 h at 50°C with crude fungal preparations having an α-galactosidase activity equivalent to 64 units μg^?1 protein, brought about a mean decrease of 82·3% for stachyose and 93·3% for raffinose. These results show that the enzyme treatment was more effective in removing the raffinose-family oligosaccharides and hence could be a useful technique for control of the flatulence-inducing activity of cowpea flours.     

Oligosaccharides, Antinutritional Factors, and Protein Digestibility of Dry Beans as Affected by Processing

Dry beans (Phaseolus vulgaris) were subjected to soaking, cooking or a combination of both prior to fermentation, and then assessed for oligosaccharides, antinutritional factors and in-vitro protein digestibility. Results showed an important decrease in raffinose oligosaccharides and antinutritional factors. However, an increase of trypsin inhibitor and tannin contents occurred respectively in cooked or soaked-cooked fermented beans and in raw or soaked fermented beans. Appreciable improvement in in-vitro protein digestibility was only observed in cooked or soaked-cooked beans. After fermentation, the largest decreases were observed in soaked-cooked beans (92.75%) for raffinose, in cooked beans (31.57%) for phytic acid, in soaked beans (90.86%) for stachyose, and in raw beans for trypsin inhibitor (38.77%). The highest increase due to fermentation was observed in raw beans for in-vitro protein digestibility (1.73%).     

ASSESSMENT OF OXIDATION IN HEATED SAFFLOWER OIL BY PHYSICAL, CHEMICAL AND SPECTROSCOPIC METHODS

Safflower oil was heated at 180C by static heating in an open pan or in an oven, or by heating through intermittent heating-cooling cycles (as in frying) over a period of 8 h. The extent of deterioration of the oil was followed by measurement of physical characteristics such as color and viscosity and the chemical indices such as free fatty acid, peroxide, iodine, conjugated diene and triene values, unsaponifiable matter and oxidized fatty acids. The extent of oxidation was also assessed by infrared (IR) and nuclear magnetic resonance (NMR) spectroscopic techniques through analysis of oxidized fatty acids. The results indicated that heating in open pan caused deterioration in oil faster than in other treatments. Furthermore, the IR, and NMR studies of the oil heated in an open pan indicated cross polymerization while during oven heating and frying cross polymerization was not observed.     

Changes in some components of soymilk during fermentation with the basidiomycete Ganoderma lucidum

Soymilk was fermented with the basidiomycete Ganoderma lucidum WZ02 and the changes in the contents of polysaccharide, sugars, crude protein, B-vitamins, free amino acids and isoflavones were analyzed. Polysaccharide and crude protein were increased by the fermentation of G. lucidum while most free amino acids were reduced. The flatulence factor (e.g. stachyose and raffinose) was significantly decreased and stachyose was not detected after 72 h of fermentation. The contents of thiamin, riboflavin, and niacin were increased during the fermentation. Most of isoflavone glycosides were converted to aglycones and the contents of daidzein and genistein were increased by the fermentation of G. lucidum. The results suggested that fermentation by G. lucidum could improve the acceptability and health properties of soymilk.     

Oligosaccharide Content of 20 Varieties of Cowpeas in Nigeria

Mature dry seeds of 20 varieties of cowpeas (Vigna unguiculata) grown in Nigeria were analyzed for their sucrose, raffinose and stachyose content. The dry seeds were ground into powder, extracted with 80% ethanolandthe extract analyzed by paper chromatography using a mixture of n-butanol, ethanol, water and ammonia solution 8:1:2:1 v/v). The results show a progressive decrease in raffinose and stachyose content with dehulling and cooking and an increase in sucrose level after cooking. The average content of the sugars in whole beans on dry weight basis was sucrose 0.8%, raffinose 2.6% and stachyose 3.3%. The average content for dehulled raw beans were sucrose 0.7%, raffinose 1.8% and stachyose 2.4% while in cooked beans it was 1.6%, 1.3%, and 1.8%, respectively.     

Enhanced bioaccessibility of β‐carotene from yellow‐orange vegetables and green leafy vegetables by domestic heat processing

Effect of heat treatment involved in domestic cooking on the bioaccessibility of β‐carotene from yellow‐orange as well as green leafy vegetables was evaluated. Heat treatment of these vegetables by pressure‐cooking, stir‐frying and open‐pan boiling had a beneficial influence on the bioaccessibility of β‐carotene. The extent of increase in the per cent bioaccessibility of β‐carotene as a result of pressure‐cooking was 21–84%. Stir‐frying in presence of a small quantity of oil brought about an enormous increase in the bioaccessibility of β‐carotene from these vegetables, the extent of increase being 67–191%. Open‐pan boiling of vegetables increased the bioaccessibility of β‐carotene in the range 23–36%. Thus, among the three domestic heat processing methods, stir‐frying results in maximum bioaccessibility of this provitamin. The use of suitably heat‐processed vegetable sources of β‐carotene could form a dietary strategy to derive this micronutrient maximally by the population dependent on plant foods.     

Effect of cooking on the composition of beans (Phaseolus vulgaris L.) and chickpeas (Cicer arietinum L.)

The effect of cooking on levels of nutrients and anti-nutritional factors in beans and chickpeas was investigated. Significant (p < 0.05) variation existed among the beans and chickpeas with respect to their crude protein, starch, soluble dietary fiber (SDF), insoluble dietary fiber (IDF), total dietary fiber (TDF), resistant starch (RS), trypsin inhibitor activity (TIA), mineral, phytic acid, tannin, sucrose and oligosaccharide (raffinose, stachyose and verbascose) contents. Cooking beans and chickpeas in water significantly increased protein, starch, SDF, IDF, TDF, Mn and P contents (on a dry weight basis), whereas reduced ash, K, Mg, TIA, tannin, sucrose and oligosaccharide contents were observed. Colored beans (black, cranberry, dark red kidney, pinto and small red bean) contained tannins, whereas little tannin in white-colored beans (great northern and white pea bean) and chickpeas (Desi and Kabuli type) was detected.     

Effect of Processing on Certain Antinutrients in Cowpeas (Vigna unguiculata)

Four Nigerian cultivars of cowpeas were analyzed for raffinose, stachyose, phytic acid, tannins, and trypsin inhibitory activity after dehulling, cold-soaking, hot-soaking, and cooking as ewa-ibeji and moin-moin (two popular Nigerian cowpea foods). Dehulling decreased stachyose and removed the tannins. Hot-soaking caused a significant reduction in stachyose and trypsin inhibitory activity. Ewa-ibeji and moin-moin contained similar quantities of antinutrients, except for tannins which were absent in moin-moin.     

Influence of Various Cooking Methods on the Concentrations of Volatile N‐Nitrosamines and Biogenic Amines in Dry‐Cured Sausages

Abstract: N‐nitrosamines, biogenic amines, and residual nitrites are harmful substances and are often present in cured meats. The effects of different cooking methods (boiling, pan‐frying, deep‐frying, and microwave) were investigated on their contents in dry‐cured sausage. The various N‐nitrosamines were isolated by a steam distillation method and analyzed by gas chromatography mass spectrometry (GC‐MS). The biogenic amines were determined after extraction with perchloric acid as dansyl derivatives by high‐performance liquid chromatography (HPLC) method. The results showed that initial dry‐cured raw sausage contained 5.31 μg/kg of total N‐nitrosamines. Cooking by deep‐frying or pan‐frying resulted in products having the highest (P < 0.05) contents, compared with boiling or microwave treatments, which were not different from the raw. Although frying increased the content of N‐nitrosodimethylamine (NDMA), N‐nitrosodiethylamine (NDEA), and N‐nitrosopyrrolidine (NPYR), it decreased the contents of histamine and cadaverine. Boiling and microwave treatments decreased the total biogenic amines significantly (P < 0.05). Residual nitrite was significantly reduced by cooking treatments. The results suggest that boiling and microwave treatments were more suitable methods for cured meat. Practical Application: N‐nitrosamines and biogenic amines are considered potentially harmful substances to humans and often present in dry‐cured sausage. Different cooking methods may effect the content of these harmful substances. However, little information exists on the different cooking methods on dry‐cured meats.