Effect of Bitter Gourd (<Emphasis Type="Italic">Momordica charantia</Emphasis>) on Glycaemic Status in Streptozotocin Induced Diabetic Rats

Bitter gourd (Momordica charantia), a commonly consumed vegetable is used as an adjunct in the management of diabetes mellitus. A study was carried out to examine the effect of edible portion of bitter gourd at 10% level in the diet in streptozotocin induced diabetic rats. To evaluate the glycaemic control of bitter gourd during diabetes, diet intake, gain in body weight, water intake, urine sugar, urine volume, glomerular filtration rate and fasting blood glucose profiles were monitored. Water consumption, urine volume and urine sugar were significantly higher in diabetic controls compared to normal rats and bitter gourd feeding alleviated this rise during diabetes by about 30%. Renal hypertrophy was higher in diabetic controls and bitter gourd supplementation, partially, but effectively prevented it (38%) during diabetes. Increased glomerular filtration rate in diabetes was significantly reduced (27%) by bitter gourd. An amelioration of about 30% in fasting blood glucose was observed with bitter gourd feeding in diabetic rats. These results clearly provided experimental evidence that dried bitter gourd powder in the diet at 10% level improved diabetic status signifying its beneficial effect during diabetes.     

Effects of Feeding Potato Pulp on Cholesterol Metabolism and Its Association with Cecal Conditions in Rats

To clarify the functional properties of potato pulp (PP), a waste product resulting from extraction of starch from potatoes, we examined the effects of PP on cholesterol metabolism and cecal conditions in rats. Plasma total cholesterol (T-Chol) levels were lower in rats fed a PP-supplemented diet for four weeks than in those fed a control diet. Cecal pH was lowered due to an increase in the levels of cecal total short-chain fatty acids, especially butyrate, in the PP group compared to the control group. Furthermore, animals fed with the PP-supplemented diet showed increased cecal ratios of Lactobacillus and Clostridia and decreased cecal ratios of Bacteroides and Gammaproteobacteria with slightly negative and positive correlations with plasma T-Chol levels, respectively. In conclusion, ingestion of PP for four weeks is likely to improve both cecal conditions and cholesterol metabolism, suggesting that PP has prebiotic effects.     

Conversion of Potato Starch and Peel Waste to High Value Nanocrystals

The present study aimed to convert starch and potato peel waste to nanocrystals. Starch nanocrystals were prepared using two methodologies: direct acid hydrolysis and enzyme pretreatment followed by acid hydrolysis. Direct hydrolysis broke down the starch granules to nanocrystals in 12 days. Enzyme pretreatment with starch hydrolytic enzymes (α-amylase and amyloglucosidase) reduced the time for preparation of starch nanocrystals by 6 days. Starch nanocrystals of optimum size were obtained with both the treatments and the resultant size ranged from 10 to 50 nm. Nanocrystals were disk-like platelets in appearance. Cellulose nanocrystals were derived from cellulosic material in the potato peel. Cellulose was isolated from peel waste with alkali treatment. Further, cellulose nanocrystals from potato peel and cellulose microcrystalline were prepared by acid hydrolysis. Microscopic images revealed that the aqueous suspension of cellulose nanocrystals derived from potato peel were single rod shaped, whereas those derived from cellulose microcrystalline were rod-like nanoparticles, agglomerated in the form of bundles including some of the rods in single units (well separated). The size of potato peel nanocrystals ranged from 40 to 100 nm (length) and cellulose microcrystalline ranged from 4 to 20 nm (diameter) by 110 to 250, given 4 to 20 nm (length), respectively. As starch nanocrystals as well as cellulose nanocrystals are derived from biopolymer, both can be considered safe for humans and the environment. Moreover, the biodegradable nature of these nanocrystals makes them superior over metallic nanoparticles, particularly in the field of nanocomposites.     

Utilization of alkaline potato peel waste by fermentation,amylase production byAspergillus foetidus NRRL 337, and alcoholic fermentation

Aspergillus foctidus NRRL337 was cultured on hydrochloric acid neutralized waste from the dry caustic potato peeling process. Alpha-amylase yields of 26–40 SKB units/ml and maltase yields of 6 to 10 units/ml were obtained. The fermented mixture filters very easily to yield an amylase containing liquor and mycelium. Alcoholic fermentation of additional peel waste using the above for amylolytic conversion gave alcohol yields of up to 90% on a stoichiometric carbohydrate basis. This work was done to demonstrate the utility of dry caustic peel waste as a starting material for fermentation processes.     

The Protective Effect of Fucoidan in Rats with Streptozotocin-Induced Diabetic Nephropathy

Diabetic nephropathy (DN) has long been recognized as the leading cause of end-stage renal disease, but the efficacy of available strategies for the prevention of DN remains poor. The aim of this study was to investigate the possible beneficial effects of fucoidan (FPS) in streptozotocin (STZ)-induced diabetes in rats. Wistar rats were made diabetic by injection of STZ after removal of the right kidney. FPS was administered to these diabetic rats for 10 weeks. Body weight, physical activity, renal function, and renal morphometry were measured after 10 weeks of treatment. In the FPS-treated group, the levels of blood glucose, BUN, Ccr and Ucr decreased significantly, and microalbumin, serum insulin and the β2-MG content increased significantly. Moreover, the FPS-treated group showed improvements in renal morphometry. In summary, FPS can ameliorate the metabolic abnormalities of diabetic rats and delay the progression of diabetic renal complications.     

马铃薯皮中黄酮类物质测定及含量

以马铃薯皮为试验材料,研究了黄酮类化合物提取方法,获得了提取马铃薯皮中黄酮类化合物的最佳条件,测量了马铃薯皮中体现抗氧化性的黄酮类化合物的含量。试验中,对马铃薯皮中黄酮类化合物进行了提取、分离,以1,1-二苯基-2-三硝基苯肼(1,1-Diphenyl-2-picrylhydrazyl radical 2,2-Diphenyl-1-(2,4,6-trinitrophenyl)hydrazyl,DPPH)的清除率作为马铃薯皮中提取的黄酮类化合物含量及抗氧化活性的评价指标。通过单因素试验,确定提取溶剂、温度、时间、料液比等对提取结果的影响程度。并在单因素试验的基础上设计4因素3水平的正交试验,从而确定马铃薯皮中黄酮类化合物的最佳提取条件。结果表明,马铃薯皮中黄酮类抗氧化物的提取最佳条件为50℃的温度下用80%丙酮溶液按照料液比1:10的比例提取,提取时间为3 h。在此条件下测得DPPH的清除率为84.62%。在最佳提取条件下提取马铃薯皮中黄酮类化合物,并测得每克烘干后的马铃薯皮中含有约10.95 mg的黄酮类物质,与其它类果实果皮中具有相似的抗氧化活性的黄酮类物质的含量相比明显较高。     

Nutritional responses of rats fed mixtures of plant and animal proteins

Twenty four male rats (45–65 g) were used to determine the nutritional responses to mixed plant and animal protein diets. Rats were fed various mixtures of sorghum (S), pigeon pea (PP), bread fruit (TAP) plus crayfish (CR) to provide 1.6 g N/100g of daily diet for a 35-day study period. Three different diets were fed to 6 rats assigned to each diet on the basis of body weight. Combination of PP:CR caused increases in N intake and retention, weight gain, and PER higher than for those of the other test groups. Its values for N intake and retention, and BV were higher than for those of the control except for food intake, NPU, weight gain and PER. Substitution of CR (20%) with TAP and PP as supplements to S decreased food intake, weight gain and PER and increased N intake, digested and retained N, NPU and BV. The results appear to indicate that (a) PP:CR blend was better than other blends as judged by the parameters, and (b) TAP and PP were superior to CR alone as supplement to S.     

Chitosan Oligosaccharide Alleviates Abnormal Glucose Metabolism without Inhibition of Hepatic Lipid Accumulation in a High-Fat Diet/Streptozotocin-Induced Diabetic Rat Model

This study investigated the effects of chitosan oligosaccharide (COS) on glucose metabolism and hepatic steatosis in a high-fat (HF) diet/streptozotocin-induced diabetic rat model. Male Wistar rats were divided into: (1) normal control (NC group), (2) HF diet (HF group), (3) streptozotocin (STZ)-induced diabetes with HF diet (DF group), and DF group supplemented with (4) 0.5% COS (D0.5F group), (5) 1% COS (D1F group), and (6) 5% COS (D5F group) for 4 weeks. COS supplementation significantly decreased the plasma glucose, BUN, creatinine, uric acid, triglyceride (TG), and total cholesterol (TC) levels, and hepatic glucose-6-phosphatase activity, and significantly increased hepatic hexokinase activity and glycogen content in diabetic rats; but the increased hepatic TG and TC levels could not be significantly decreased by COS supplementation. Supplementation of COS increased superoxide dismutase activity and decreased lipid peroxidation products in the diabetic rat livers. COS supplementation significantly increased phosphorylated AMP-activated protein kinase (AMPK) protein expression, and attenuated protein expression of hepatic phosphoenolpyruvate carboxykinase (PEPCK) and phosphorylated p38 and renal sodium-glucose cotransporter-2 (SGLT2) in diabetic rats. These results suggest that COS may possess a potential for alleviating abnormal glucose metabolism in diabetic rats through the inhibition of hepatic gluconeogenesis and lipid peroxidation and renal SGLT2 expression.     

Functional Properties and Dietary Fiber Characterization of Mango Processing By-products (Mangifera indica L., cv Ataulfo and Tommy Atkins)

Several reports have focused on utilization of post-harvest residues of crops, while neglecting those residues produced by mango processing. These residues represent a waste of nutrients and a source of environmental contaminants. Such by-products could be valuable sources of dietary fiber (DF), antioxidant compounds, and single carbohydrates. The aim of this study was to evaluate some functional properties (FP), and the content of DF and polyphenols (PP) of the peel and coarse material obtained from residues during the industrial processing of Ataulfo and Tommy Atkins mangoes. The total dietary fiber (TDF) content was about 225 mg/g and 387 mg/g (dry weight) for the coarse material and the peel, respectively, from which soluble dietary fiber represented 23 and 42 %, respectively. The main neutral sugar identified was rhamnose, especially in peels; the klason lignin (KL) content was 92 mg/g, which highlights the Ataulfo peel (Ataulfo-P) and the Tommy Atkins peel (Tommy Atkins-P). The extractable PP content in Ataulfo-P was higher than in Tommy-Atkins-P, and interesting data for non-extractable PP were obtained in the residues. FP as swelling, water holding, oil holding, and glucose absorption in the residues was studied, obtaining better functional properties when compared to cellulose fiber. The results show that mango industrial by-products, mainly from the Ataulfo-P variety, could be used as ingredients in food products because of their functional properties as well as their DF and PP content.     

咖啡果皮粉对饼干品质和淀粉消化性的影响

咖啡果皮是咖啡加工过程中产生的副产物,约占咖啡果实的50%,测定结果显示咖啡果皮中含有丰富的膳食纤维,总膳食纤维的含量可达64.80%,且脂肪含量低,仅为1.62%。但咖啡果皮仅有一小部分被用作堆肥和动物饲料,大部分被丢弃,造成了不可忽视的环境问题和资源浪费。为了探寻咖啡果皮在焙烤食品中的加工利用,本研究利用超微粉碎的咖啡果皮0%、5%、10%、15%、20%替代小麦粉来制作饼干,通过测定饼干的含水率、膳食纤维的含量、DPPH清除率、淀粉消化性能、血糖生成指数、色泽、质构及感官性状,发现与对照组（0%）相比,随着咖啡果皮粉替代量的增加,饼干的含水率从6.57%下降至5.32%,膳食纤维含量和DPPH清除率显著增加,分别从1.84%增加至10.65%,从2.89%增加至36.69%,淀粉的消化率、C_∞和k值与咖啡果皮粉的替代量呈负相关,最终预测的饼干血糖生成指数从91.16降至66.35,但5%、10%、15%替代量的饼干仍为高血糖生成指数的食物,色泽中L^*和b^*值逐渐下降,而a^*值在5%和10%替代量时超过了对照组,饼干呈现咖啡果皮的棕红色,另外,饼干的硬度和咀嚼性逐渐增加,但在5%替代量时硬度增加并不显著（P<0.05）,脆性、恢复力、粘结力和弹性均逐渐下降,当咖啡果皮粉添加量为5%时,可获得理想的感官评分,尤其是在色泽和气味上的得分达到最高,分别为4.8和4.7分。结果表明,咖啡果皮粉可以考虑作为一种饼干的配料来增加消费者对膳食纤维、抗氧化性物质和低糖化淀粉的摄入,该研究结果为咖啡果皮的综合利用提供理论依据。     

Beta cell protective effects of sodium tungstate in streptozotocin-induced diabetic rats: glycemic control, blockage of oxidative stress and beta cell histochemistry

Background: Diabetes is a major public health problem. The development of new therapies that are able to improve glycemia management and even to cure diabetes is of great interest. In this study, protective effects of sodium tungstate against STZ-induced beta-cell damages were investigated. Methods: Sixty rats were divided into six groups: control, diabetic, sodium tungstate treated diabetic rats from one week before STZ injection (TDB), food-restricted diabetic (FRD), tungstate treated control, sodium tungstate treated diabetic rats from one week after STZ administration (TDA). We evaluated serum insulin, glucose and glucose tolerance; liver glycogen content, glucokinase (GK) activity; blood and pancreas antioxidant power, lipid peroxidation; and fuchsin-aldehyde histochemical staining of beta-cells. Results: Blood glucose levels of TDB group were lower than other diabetic groups (P<0.01). Blood insulin levels of all diabetic groups were lower than controls (P<0.01). Glucose intolerance improved in TDB animals. Blood and pancreas antioxidant power, liver glycogen contents and GK activities and granulated beta cells increased in TDB rats in comparison with other diabetic groups (P<0.01). Likewise, lipid peroxidation decreased significantly in TDB rats (P<0.01). Conclusions: Results suggested that sodium tungstate if administrated before STZ injection improves glycemic state by a direct effect on pancreatic beta-cells and preserves them by reducing the activity of these cells at the time of STZ injection, reducing STZ-induced oxidative stress, reducing insulin secretion, or all of the above mentioned.     

马铃薯块茎“定形”技术研究

马铃薯块茎的外形是重要的商品品质和加工品质。为使马铃薯块茎外形生长规则理想化,试验采用块茎开始膨大直径达2 cm左右时,在其外面加套简单模具,让块茎生长随模具而"定形"的方法,试验得到了较为理想的近圆柱形块茎。经测定"定形"块茎芽眼极浅,近乎平面,且稀少,比对照减少37.5%,菜用时切削量减少18.25%。"定形"块茎形状规则,清洗切削方便,利用率提高,具有一定的增值开发潜力。     

The proximate composition and glycoalkaloid content of three potato meals

The proximate composition and glycoalkaloid content of a dried potato by-product meal (tater meal) and two dried potato pulp meals (potato meal and potato meal plus 10% molasses) were determined. All three feeds demonstrated variable compositions: the tater meal averaged 8.7% moisture, 9.1% crude protein, 5.4% ether extract, 5.0% crude fiber, 4.1% ash and 56.8% nitrogen-free extract; the potato meal averaged 14.5% moisture, 6.0% crude protein, 0.5% ether extract, 9.5% crude fiber, 2.2% ash and 57.1% nitrogen-free extract; the potato meal plus 10% molasses averaged 15.3% moisture, 6.4% crude protein, 0.3% ether extract, 8.0% crude fiber, 2.6% ash and 57.8% nitrogen-free extract. The phosphorus concentration was determined to be approximately 0.2% for the three samples. Other minerals were found in lesser concentrations. The riboflavin and thiamine concentrations of the three potato meals were less than 10% of the values reported for raw potato pulp and peel. The niacin concentration was approximately 40% of the values reported for raw potato pulp and peel. Tater meal contained 11.5 mg a-chaconine and 6.5 mg α-solanine per 100g meal. Analysis of potato meal gave 15.8 mg α-chaconine and 7.8 mg α-solanine per 100g meal while the potato meal plus 10% molasses was found to contain 13.2 mg α-chaconine and 7.3 mg α-solanine per l00g meal.     

Modulatory Effect of Fenugreek Seed Mucilage and Spent Turmeric on Intestinal and Renal Disaccharidases in Streptozotocin Induced Diabetic Rats

To elucidate the effect of feeding fenugreek seed mucilage and spent turmeric (10%) on disaccharidases activities, the specific activities of intestinal and renal disaccharidases viz., sucrase, maltase and lactase were measured in streptozotocin induced diabetic rats. Specific activities of intestinal disaccharidases were increased significantly during diabetes and amelioration of these activities during diabetes was clearly visible by supplementing fenugreek seed mucilage and spent turmeric in the diet. However during diabetes renal disaccharidases activities were significantly lower than those in the control rats. Fenugreek seed mucilage and spent turmeric supplementations were beneficial in alleviating the reduction in maltase activity during diabetes, however not much change in the activities of sucrase and lactase was observed upon feeding. This positive influence of feeding fenugreek seed mucilage and spent turmeric on intestinal and renal disaccharidases clearly indicates their beneficial role in the management of diabetes.     

Antioxidant capacity, anthocyanins and total phenolics in purple-and red-fleshed potato (Solanum tuberosum L.) genotypes

Purple- and red-fleshed potatoes (Solanum tuberosum L.) were evaluated for their total anthocyanin (ACY), total phenolic (PHEN), and antioxidant capacity. The ACY and PHEN compounds were distributed throughout the tubers; however, a higher concentration was found at the stem-end than the bud-end. Although ACY and PHEN concentrations in potato peel were 0.9-to 1.6-fold higher than in potato flesh, overall contribution of the peel to ACY and PHEN contents of a potato slice was ～20%. These observations differ from the widespread idea that phytonutrients are mostly accumulated in the peel of tubers. The ACY and PHEN contents of different purple- and red-fleshed potato genotypes ranged from 11 to 174 mg cyanidin-3-glucoside/100 g fresh weight and from 76 to 181 mg chlorogenic acid/100 g fresh weight, respectively, and were genotype and location dependent. High positive correlations between antioxidant capacity and ACY and PHEN suggest that these compounds are mainly responsible for the antioxidant capacity. These results provide useful and important information for potato breeders and researchers in order to increase the antioxidant capacity and functional value of purple- and red-fleshed potatoes for the food and nutraceutical industries.     

Dynamics of phytate-zinc balance of fungi fermented cassava products (gari and flour)

Parsley is one of the medicinal herbs used by diabetics in Turkey. It has been reported to reduce blood glucose levels. In this study the effects of feeding parsley on diabetes-induced free radical mediated injury in rat aorta and heart tissues were investigated. Swiss albino rats were divided into six groups: Control, diabetic, parsley, diabetic + parsley, glibornurid, and diabetic + glibornurid. Rats were subjected to i.p. streptozotocin (STZ, 65 mg/kg) to induce diabetes. On the fourteenth day of the study, either parsley (2 g/kg) or glibornurid (5 mg/kg) were given for 28 days to the diabetic rats. Aorta and heart tissue lipid peroxidation and glutathione levels as well as blood glucose levels were determined. The results of the present study indicate that lipid peroxidation was increased and glutathione levels were decreased in both aorta and heart tissue of the diabetic rats. However, treatment of the diabetic rats with either parsley or glibornurid reversed the effects of diabetes on blood glucose, and tissue lipid peroxidation and glutathione levels.     

Enzymatic Peeling of Potato: A Novel Processing Technology

Development of an innovative biotechnological method for potato peeling, closer to the ‘ideal’ peeling conditions of the product, was the main objective of the present research. Studies on enzymatic hydrolysis of potato peel were conducted. The efficacy of enzymatic peel hydrolysis was expressed in terms of reducing sugar content of the enzyme solution in which potato peel was incubated. Enzyme screening revealed that an enzyme solution containing a cellulase-xylanase mixture and amylase in a ratio of 1:1 showed good peel hydrolyzing efficiency of peeled peels. To further maximise the peel hydrolysis, condition parameters were optimised using response surface methodology (RSM). At the optimised conditions of 60 °C, pH 6 and 4 h, the reducing sugar yield in the solution was maximum. Characterization of the potato peel using microscopic techniques (scanning electron microscopy (SEM), atomic force microscopy (AFM)) further illustrated degradation of cell wall and reduction in the surface roughness of the peel after enzymatic treatment, which could enhance peel loosening from the intact potato. To further ascertain the efficiency of the process, studies were conducted with the selected enzyme on intact potato tubers under optimised conditions. Easy removal of peel was observed in enzyme-treated potato tubers, which showed 0.52% peel loss by abrasive peeling. The present process employing enzymes could be applied for peeling of intact potato as an alternative to conventional peeling process.     

Dried green leaf powders of Jew's mellow (Corchorus), persimmon (Diosphyros kaki) and sweet potato (Ipomoea batatas poir) lower hepatic cholesterol concentration and increase fecal bile acid excretion in rats fed a cholesterol-free diet

A cholesterol-free diet containing dried powder of Jew's mellow leaves, persimmon leaves or sweet potato leaves respectively at 5% level as dietary fiber was fed to male Sprague-Dawley rats for about one month. The experiment was conducted twice except for sweet potato leaves. In the groups fed the diet mixed with powders of any of the three different dried green leaves, the hepatic cholesterol concentration significantly decreased. Such lowering was not observed in serum cholesterol concentration compared with the control (cellulose) group. A significant increase in fecal weight was observed in all the groups fed the green leaf samples. All the dried green leaves increased fecal excretion of bile acids per gram or per day compared with the control group in both experiments, but only the dried Jew's mellow leaves showed an increased excretion of neutral sterols. These results suggest that lowering of hepatic cholesterol by powdered green leaves is not necessarily due to the same factor, but to the increased fecal excretion of bile acids due to inhibited enterohepatic circulation in animals given these samples.     

The nutritional value of diets based on starchy foods and common beans

Feeding trials were carried out to determine the minimum amount of common beans, with and without methionine supplementation, needed to obtain positive weight gains of rats fed cassava, sweet potato, plantain and potato flours. The protein content of these materials was 1.4, 3.8, 3.1 and 9.5% on a dry weight basis as compared to 22.8% in common beans. The amount of beans added varied from 0 to 40.0% without and with 0.3% methionine. Without methionine addition, the amount of beans required to maintain body weight was 24.8% for plantain, 19.3% for cornstarch, 20.0% for cassava and 40.1% for sweet potatoes. With just potato flour in the diet, the animals gained weight. With methionine addition, the amount of beans required for body weight maintenance was: 20.1% for plantain, 10.1% for cornstarch, 14.5% for cassava, 14.6% for potato and 29.3% for sweet potatoes. Mixtures of potatoes with as little as 10% beans with methionine gave excellent protein quality values. The results confirm previous findings on sulfur amino acid contents of beans. It is of interest to point out that factors other than a low level of protein in the starchy food tested are influencing the level of beans needed in the presence or absence of methionine supplementation.INCAP Publication I-1355.     

Antidiabetic effect of essential oil from Artemisia sieberi growing in Jordan in normal and alloxan induced diabetic rats

The aim of this study was to evaluate the effects of essential oil extracted from aerial parts of Artemisia sieberi in normal and alloxan induced diabetic rats. Fifty rats were divided into five groups of 10 each. Group I normal rats received 1 mL day(-1) of dimethyl sulfoxide (control); group II normal rats received a single dose (80 mg kg(-1) b.wt.) of essential oil extract of Artemisia sieberi; group III diabetic rats received 1 mL day-of dimethyl sulfoxide; group IV diabetic rats received the oil extract (80 mg kg(-1) b.wt.); group V diabetic rats received metformin (14.2 mg kg(-1) b.wt.). All treatments were orally administered once a day for six weeks. Changes in blood glucose concentration, body weight and food and water intake were measured and the data obtained were compared with that of metformin. The essential oil extract significantly (p < 0.05) lowered blood glucose level as well as food and water intake in diabetic rats accompanied by an increase in body weight gain with no apparent side effect when compared with untreated diabetic rats. These effects were found to be closely similar to that of metformin, a common antidiabetic drug. On other hand, no apparent improvement on body weight gain in diabetic rats treated with metformin. In addition, for all parameters measured, the oil extract showed no effect in normal rats. In conclusion, the essential oil of Artemisia sieberi exhibited antidiabetic activity in alloxan-induced diabetic rats. Present findings support the possible use of the essential oil of Artemisia sieberi as a remedy for diabetes mellitus in humans.