Carbohydrate and protein composition of banana pulp and peel as influenced by ripening and mold contamination

The effects of firewood-obtained ash and a fruit mold, Botryodiplodia theobromae, on the total proteins and some carbohydrate constituents of the banana fruit were investigated. A slight decrease in moisture content of the ash-ripened peel was recorded. Fruit infested with the mold showed a complete loss of glucose and fructose and a drastic reduction in total sugars. Cellulose was found to remain fairly constant during ripening while the starch content fell as ripening progressed. Low levels of proteins were recorded both in the peel and pulp of fruit.     

菝葜果实主要成分及氨基酸含量分析

对菝葜(Smilax china L.)果实不同部位的主要成分及氨基酸含量进行分析。结果表明：与种子、果皮相比,菝葜果肉的含水量、还原糖含量、总糖含量均最高,果肉的总酸含量与种子接近,色素物质主要集中在果皮内。种子的蛋白质、脂肪及淀粉含量均最高,果皮的蛋白质含量最低,果肉的淀粉含量最低。果肉和种子均含有 17 种氨基酸,其中包括7 种人体必需氨基酸,除了苏氨酸和亮氨酸外,其余几种必需氨基酸的比例均超过或接近WHO/FAO 标准模式。因此,菝葜果实具有较高的食用价值,还可以进行精深加工。     

不同提取方法对面包果淀粉性质的影响

本文采用湿磨法、碱法、中性蛋白酶法提取面包果淀粉,研究三种不同提取方法对面包果淀粉性质的影响。结果表明:湿磨法、碱法、中性蛋白酶法的提取率分别为23.90%、66.25%、66.05%,而碱法、中性蛋白酶法无显著性差异(P>0.05);面包果淀粉提取破损情况:碱法(4.20%)>中性蛋白酶法(2.28%)>湿磨法(1.92%);湿磨法提取面包果淀粉中蛋白质和脂肪残留量最多,碱法和中性蛋白酶法的残留量相差较小;不同方法提取的面包果淀粉溶解度和膨胀度均随温度的升高而升高,湿磨法提取的面包果淀粉溶解度和膨胀度均最大,碱法和中性蛋白酶法相差较小。经综合评价得出,中性蛋白酶法为面包果淀粉的最佳提取方法。本研究为面包果淀粉提供了一种新型绿色提取工艺,以期为面包果淀粉获得更加经济环保的工业化生产提供理论依据。     

Effect of soaking process on nutritional quality and protein solubility of some legume seeds

Legume seeds (soy bean, lupin and bean seeds) were soaked in 0.5% sodium bicarbonate in attempt to evaluate their nutritional quality and protein solubility index. Soaking process led to an increase in the hydration coefficient, seed weight, total protein, ash, fat, fiber, while non protein nitrogen, total carbohydrates, starch, stachyose, raffinose, reducing sugars, and minerals (except Na) were decreased. All antinutritional factors such as phytic acid, tannin, trypsin inhibitor and hemagglutinin activity were decreased during soaking in 0.5% sodium bicarbonate; it was the same for the protein solubility in different solutions, while the in-vitro protein digestibility and available lysine were increased.     

Composition of Flours from Samoan Breadfruit

Flours from the pulp of seven varieties of breadfruit (Artocarpus altilis) at various stages of maturity were prepared and analyzed. Crude protein content ranged from 2.90–5.08%, crude fat from 0.80–1.93%, crude fiber from 2.87–6.56%, ash from 1.90–4.08%, total sugars from 10.0–31.8%, and starch from 53.4–75.7% depending on variety and stage of maturity. Fructose was the predominant sugar in less mature fruits, becoming less so in comparison to glucose and sucrose as maturation progressed. The proportion of unsaturated to total fatty acids in the lipid component varied between varieties from 41–64%. Observed levels of iron, sodium, phosphorus, calcium, and potassium may be significant in a nutritional sense.     

Chemical evaluation of nutritive value of the fruit of African starapple (Chrysophyllum albidum)

The nutritive value of African starapple, Chrysophyllum albidum, was evaluated chemically. Chemical analyses were carried out on the peel and the edible pulp. The peel was shown to contain 58·9% moisture, 6·1% protein, 12·4% lipid, 4·6% ash, 62·4% carbohydrate and 14·5% crude fibre. The pulp contained 67·5% moisture, 8·8% protein, 15·1% lipid, 68·7% carbohydrate, 4·0% crude fibre and 3·4% ash.Analysis of the fruit for minerals showed the peel to contain (in mg/100 g dry matter): calcium, 250; potassium, 1175; sodium, 12; copper, 2·0; magnesium, 90; zinc, 3·8; iron, 200; and phosphorus, 76·8. The pulp contained (in mg/100 g dry matter): calcium, 100; potassium, 1175; sodium, 10; copper 2·0; magnesium, 75; zinc, 3·2; iron, 10; and phosphorus, 75·4. The peel contained ascrobic acid 239·1 mg/100 g and the pulp, 446·1 mg/100 g. Some toxicants were shown to be present. The peel contained 264 mg/100 g tannins and the pulp, 627 mg/100 g.The total oxalate content in the peel was 211 mg/100 g and in the pulp, 167 mg/100 g. The hydrocyanic acid content was 5·4 mg/100 g in the peel and 6·8 mg/100 g in the pulp. The phytic acid content was 0·8 mg/100 g in the peel and 1·6 mg/100 g in the pulp.The contribution of the fruit of African starapple to the nutrient requirements of consumers is discussed as well as other possible uses for the fruit.     

Nutritional potential and functional properties of tempe produced from mixture of different legumes. 1: Chemical composition and nitrogenous constituent

Fermented foods such as Tempe represent a technological alternative for a great variety of legumes and combination of them to improve their nutritional quality and to obtain edible products with palatable sensorial characteristics. The chemical composition, carbohydrate fraction and nitrogenous constituents were investigated for individual different legumes, i.e. faba bean; lupine, chickpea; peas and their mixture before and after fermentation by Rhizopus oligosporus. Tempe had a higher (P < 0.05) protein and fibre content compared with legume mixtures before fermentation, while it had a lower fat, ash and carbohydrate contents. Also, reducing and non‐reducing sugars, stachyose as well as raffinose were reduced after fermentation of legume mixtures. A significant reduction was observed in non‐protein nitrogen and protein nitrogen, while total nitrogen and true protein were increased.     

Chemical composition of unripe (green) and ripe plantain (Musa paradisiaca)

The proximate chemical composition, the carbohydrate constituents and the amino acid make-up of green and ripe plantain were determined. The quantity of total sugars considerably increased during ripening from 3.0 to 31.6% in the peel and from 1.3 to 17.3% in the pulp while starch concentration decreased from 50 to 35% and from 83 to 66% in the skin and the pulp, respectively. The skin was richer in cellulose (10%) and hemicellulose (13%) than the pulp which had 1.4% cellulose and 1.3% hemicellulose. The pulp protein was abundantly rich in arginine, aspartic acid and glutamic acid. Methionine was present in the lowest amount with tryptophan and cystine conspicuously being absent.     

Chemical and nutritional assessment of sweetpotato proteins

The solubility of sweetpotato nitrogen increased outside the pH range 3-6 for the pulp, and 2-5 for the peel of the two varieties namely, "Abees" and "Giza 69". The minimum nitrogen extractability occurred between the pH range 3-4, and 4-5 for the peel and pulp, respectively. The sweetpotato protein isolates were prepared separately from both peel and pulp of the two varieties. The former had the highest values of carbohydrates and ash while the latter had the highest values of protein and fat. The in-vitro digestibility of sweetpotato proteins and casein by pepsin-pancreatin was studied. Casein was more easily digested than the proteins of sweetpotatoes, whose digestibilities were higher in the pulp than in the peel of the two varieties. No trypsin inhibitor activity was detected in peel and pulp of both varieties under test. The effect of the variety of sweetpotatoes on the protein patterns was studied using the polyacrylamide gel electrophoresis and varietal specific patterns were obtained.     

Increasing the fat content of pancakes augments the digestibility of starch in-vitro

Carbohydrate foods that breakdown rapidly during digestion are known to have the highest glycemic index (GI) values. It is known that lipid-starch complexes can form in foods; however how this may enhance the resistance of starch to enzyme hydrolysis is unknown. The aim of this study was to examine the effect of adding different fats to a carbohydrate rich food on the digestibility of starch in-vitro. Three sets of carbohydrate-lipid emulsion (CLE) batters in the form of pancakes were prepared as 1) low fat (20.3% mass as fat), 2) medium fat (32.7% mass as fat) and 3) high fat (45.1% mass as fat). For each set of CLE a control (containing no added fat), saturated fat (butter), polyunsaturated fat (sunflower oil), monounsaturated fat (olive oil) and medium chain triglyceride saturated fat (MCT oil) was prepared. The CLEs were digested in-vitro and sugars released measured. The results indicated that increasing the concentrations of fat in the CLE augmented sugar release (p < 0.001). The results also showed that there were differences between the different types of fats in the CLE (p < 0.001). The primary differences existed between the control and all the other CLEs, as well as between the MCT CLE and all other CLEs. Correlation analysis showed an inverse relationship between the amount of remnants remaining after digestion and the sugars released from the CLE (p = 0.004 and p = 0.014). This research indicates that adding fat to a carbohydrate food will increase the digestibility of starch and release of sugars from the food which may impact on glycemic response.     

Changes in carbohydrate contents of germinating cowpea seeds

A decrease in the concentration of total carbohydrates was observed during 144 hours' germination of three cowpea varieties. However, whilst starch, raffinose, stachyose and verbascose levels decreased, the reducing sugars, including glucose and fructose, increased. Starch was the major carbohydrate and about 50% of it was hydrolysed after 144 hours' germination. Changes also occurred in the concentration of the unavailable carbohydrates. Lignin contents increased slightly while hemicelluloses and celluloses decreased. The above-mentioned changes, occurring during germination, appear to have a favourable effect on the nutritional value of cowpea varieties.     

Composition and Pasting Properties of Breadfruit (Artocarpus communis Forst) from South-West States of Nigeria

Breadfruit (BF) is an underutilised crop in Nigeria. Information on its composition and the behaviour of its flour during cooking are important requirements for enhancing the utilisation of BF. Flours of BF obtained from three towns in South-West Nigeria were analysed for their chemical and pasting properties. Starch, crude fibre, ash, fat, protein and pasting properties were evaluated. Starch was the predominant carbohydrate, representing about 60.4 to 65.8% in the pulp and 47.5 to 57.5% in the peel. Crude fibre values varied from 6.31 to 9.04%. There was no significant difference between the crude fibre contents of the pulp and peels. Ash content ranged from 2.77 to 4.78% with the peels having significantly higher values than the pulp. Fat content ranged from 0.43 to 0.65%. The pulps had significantly higher protein content than the peels. Peak viscosity varied significantly across locations with the peels having significantly lower viscosity than the pulps. The peels were significantly hot stable with breakdown viscosity values of 6.92 to 7.95 RVU compared to the pulps (72.33 to 210.77RVU). Final viscosity of the pulp was higher than that of the peels. Higher setback viscosity values were observed in the pulps than the peels and the former cooked in significantly shorter time (3.67 to 3.77 min) than the peels (8.93 to 8.99 min). The study revealed considerable differences in the composition of breadfruit grown in different locations in Nigeria.     

Cassava Starch or Amylose Effects on Characteristics of Cassava (Manihot esculenta Crantz) Extrudate

Blends of cassava flour with cassava starch or amylose were processed on a Wenger X-5 laboratory extruder. Cassava starch added to cassava flour increased total carbohydrate in feed, reducing yellow color, water absorption and extrudate bulk density but increased expansion, product moisture, water solubility and total reducing sugars. Amylose addition increased extrudate surface regularity with reduced water solubility, total reducing sugars, and bulk density. Expansion was highest in mixtures containing 60% amylose. Textural properties of extrudate increased on addition of amylose or cassava starch. Differences in microstructures existed between cassava flour and cassava starch extrudate.     

Changes in carbohydrates of germinating fenugreek seeds (Trigonella foenum graecum L.)

The effect of germination at 25 °C for 96 h in the dark on the carbohydrates of fenugreek seed was investigated. Reducing, total reducing, non-reducing sugar, and pentosan contents increased. Polysaccharides estimated as starch decreased. Fenugreek contained mucilage (18%), which decreased considerably during germination. The decline in mucilage content was accompanied by a drop in galactan content. Total pectic content did not change, but there was a decline in the high methoxy pectin content, while protopectin, and the low methoxy pectate salts of calcium and magnesium increased. The 70% ethanol soluble carboydrates were chromatographically determined. Fenugreek seeds contained sucrose, raffinose, stachyose, and an unidentified sugar ( I ). A marked increase in sucrose content was observed after germination. Raffinose, stachyose and the unknown sugar ( I ) decreased, while another unknown ( II ) appeared. The two unknown sugars may be members of the raffinose family. Maltose and fructose appeared in measurable amounts after germination.     

Physico-chemical and acceptability of rabadi (a fermented soya flour product) as affected by cooking and fermentation time

Various food‐processing techniques like malting, roasting, soaking, germination, fermentation, etc. are known to enhance nutritive value and acceptability of different food products. The present study deals with the biochemical analysis and acceptability tests of soya flour rabadi, which was made by fermentation before and after cooking at different time intervals. There was a trend towards increase in moisture, ash, total carbohydrate, calcium, total soluble sugars, reducing sugars, non‐reducing sugars, amylase, glutamate oxaloacetate transaminase enzymatic activities and titrable acidity, whereras a trend towards decrease was found in crude protein, fat, fibre, energy, starch, total phenols and glutamate pyruvate transaminase enzyme activity. Major biochemical changes occurred after 8 h fermentation. In sensory evaluation also, samples fermented for 4 and 8 h after cooking got higher scores than all other samples.     

Non-structural carbohydrate partitioning in Phaseolus vulgaris after vegetative growth

This study provides information on the concentration and quantity of starch, reducing sugars, total sugars, and non-reducing oligosaccharides in the organs of the common bean plant (Phaseolus vulgarisL cv Jamapa) during growth. The following observations were made: (1) the root, stems and branches were temporary carbohydrate storage organs; (2) until 80 days after sowing (DAS), the leaves were the major contributors to the non-structural carbohydrates of the whole plant; (3) during the developmental period studied, non-structural carbohydrate content in the rachis and pulvinus changed frequently; (4) the pod walls contained between 5 and 8% of total sugars at 72 DAS and by maturity soluble sugars diminished to less than 1%; (5) during seed growth (until 80 DAS), the pod walls contained between 11 and 18% starch (dry weight basis) and by maturity this carbohydrate had decreased to 2% of dry weight; and (6) starch represented the major non-structural storage carbohydrate in mature seeds (29%), as opposed to soluble sugars, which amounted to 2·3% of the dry weight.     

板栗中碳水化合物的种类和抗消化性

采用HPLC-RI 和常规化学方法研究板栗中碳水化合物的种类与抗消化特性的关系。结果表明：板栗中淀粉含量为35.77%,直链淀粉所占比例为30.16%;生板栗中抗性淀粉含量为27.44%,占总淀粉的比例为68.93%;熟板栗中抗性淀粉含量为5.46%,占总淀粉的比例为13.36%;熟板栗中抗性淀粉的含量在冷藏24h 内呈上升趋势,24h 后含量变小。板栗纯淀粉中的抗性淀粉含量随时间延长呈上升趋势,在48h 内,抗性淀粉的含量由14.66% 上升到了20.15%;板栗中可溶性糖主要有蔗糖、鼠李糖,此外还有葡萄糖、果糖、麦芽糖和棉子糖,而棉子糖不能被人体消化吸收。结论：板栗中高含量的抗性淀粉和棉子糖是造成板栗生吃难消化,熟食易滞气的主要原因。     

Carbohydrate composition of different varieties of cowpea (Vigna unguiculata)

Twenty varieties of cowpea with the following proximate composition: dry matter, 87–94%; crude protein, 24–33% ether extract, 1–2%; crude fibre, 2–5% and ash, 2–5% were analysed for sugar contents, starch, cell wall carbohydrates and lignin. The legume seeds exhibited a total carbohydrate content ranging from 56% to 68%, the major constituent being starch. Starch values as high as 45% to 48% were obtained for some varieties although most values ranged between 37% and 42%. Ethanol-soluble sugars were verbascose, stachyose, sucrose and raffinose in varying amounts but there were only traces of fructose and glucose. Samples had total soluble sugar contents of 6% to 13%. Values for unavailable carbohydrates for most samples were 11% to 13%. Lignin was very low and ranged from 0·6% to 1·8%.     

Studies on kolanut and cashew kernels: moisture adsorption isotherm,proximate composition,and functional properties

Kolanut (Cola nitida) and cashew (Anacardium occidentale) kernels were analysed and their moisture adsorption isotherms, proximate composition, and functional properties were compared. The dried powdered sample of kolanut contained 69% carbohydrate, 18% crude fat and 3.1% ash by weight, while the cashew sample had 51% crude fat, 36% crude protein, 0.3% ash and 3.4% carbohydrate. These differences significantly affected their relative water and oil absorption capacities, least gelation concentration, bulk density, and emulsion properties. However, both samples would retain nutritional integrity when stored in atmospheres with water activities of up to 0.68 for kolanut and 0.85 for cashew kernels. The Brunauer–Emmett–Teller (BET) and Henderson mathematical models described both isotherms with less than 2% mean relative deviation.     

Compositional changes during guava fruit ripening

Compositional changes of fruit pulp and peel during ripening of white- and pink-fleshed guava fruits were studied. The white and pink guava fruits exhibited a typical climacteric pattern of respiration. Fruit tissue firmness decreased progressively, in a similar manner, in both guava fruit types. Total soluble solids (TSS) and total sugars increased in pulp and peel of both guava types with decrease in flesh firmness. More increase in total sugars was observed after the climacteric peak of respiration. Reducing sugars and titratable acidity increased up to the full-ripe stage and then decreased. Ascorbic acid and phenolic compounds decreased continuously during ripening of the two types. The peel showed higher values of ascorbic acid, total protein and phenolic compounds than the plup. The white-fleshed guavas had higher levels of TSS, total sugars, reducing sugars. titratable acidity, phenolic compounds and ascorbic acid content then the pink-fleshed fruits.