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Recently, snack food consumption of the population almost every country over the world is likely to cause problems and health adverse effect. Snack food is a popular product consumed between meals as it is easy to consume; thus, consumption is relatively high. Crackers and cookies are quite popular snack but often contain inappropriate content, such as starch and fat. Some have high amounts of salt or sugar, which, if eaten regularly, it can cause health problem. Snack basically is made from wheat flour, which imported from abroad. However, there has been quite extensively studied in the other starches to replace wheat flour such as glutinous rice flour and cassava flour yeast. Therefore, the development of health snack products is high potential market competition. There are many ways to produce health snack such as using the oven instead of frying with oil or reducing carbohydrates. The reducing the amount of carbohydrates in food products by increasing the amount of protein in the product is an alternative interest. It is the plant protein which has few side effects. It has a direct relationship with the lower cholesterol and LDL cholesterol products. Low carbohydrate means a product has a reduced carbohydrate. The protein replacement can increase the nutritional value to the product. Cowpea (Vignaunguiculata) and other legumes are food sources that high in nutritional value. Generally, they contain approximately 50-67%of carbohydrate and 23-25%protein. Cowpea seeds present in various colors such as black cowpea, white cowpea and red cowpea. The color is caused by pigments such as anthocyanins and other flavonoids.. Besides, cowpea contains substantial amount of resistant starch, a starch resist to a digestion by enzymes in the gastrointestinal tract and cannot be absorbed in the small intestine of humans and affects blood glucose levels. This is helpful to those with diabetes. There are a varieties species and colors of cowpeas and other legumes grown in Thailand. However, only few studies related to chemical compositions, biological active ingredients, and the resistant starch content have been reported. This research aimed to study the chemical compositions, physico- chemical and functional properties of flours obtained from cowpea seeds (Vignaunguiculata) and red kidney beans (Phaseolus vulgaris). The present study also purposed to apply cowpea flour to make cookies by substitute for wheat flour. The legume seeds were prepared into two parts, decorticated legume flours and whole seed flour. All flours were analyzed for chemical compositions, physicochemical, functional, and physical properties. The seed coat obtained from the process of decortications was determined for bioactive components. The results indicated that legumes in different cultivars had significantly different in chemical compositions. The moisture contents varied between 7.80% and 12.39%. Ash, fiber and protein content were highest found in black cowpea ( wholeseeds) are 4.25%, 3.35% and 28.25%respectively. The fat, content were highest in white cowpea; wholeseeds(1.88%). Black cowpea (decorticated bean) has carbohydrate content highest(66.41%). The resistant starch content were highest in the decorticated red cowpea (9.32%) and the whole seed of red kidney beans (10.63%) while the solubilizedstarch and total starch contents were highest in decorticated and whole black / white speckled cowpea 62.91, 48.19%, 66.02 %, and 56.37%, respectively. The black cowpea (decorticated bean) had highest amino acid content (7.00 mg/100g), followed by the whole seed of red kidney beans 6.00 mg/100g. The determination of functional and physicochemical properties in cowpea seeds found that, decorticated black / white speckled cowpea has the highest peak viscosity and trough 77.16 and 74.10 (RVU) while thewhole seed showed the highest level of breakdown and pasting temperature 5.63 (RVU) and 85.61 ?C. Moreover, black cowpea indicated the greatest final viscosity and setback values, 129.86 and 57.05 (RVU), respectively. For the analysis of the energy changes using the DSC method, the different cowpeas had different gelatinization temperatures (p ? 0.05)In the study of swelling property, the red cowpea (decorticated bean and whole seed) had highest values varying between 9.96 and 9.08 g /g, respectively, while the white cowpea(decorticated bean and whole seed)had the greatest solubility ranging from 37.26 to 30.47%. The different of cowpeas had different turbidity and increased as the number of hours determining increased.The decorticated bean and whole seed black /white speckled cowpea had the greatest of water building capacity (56.70 and50.84% respectively), and black cowpea (decorticated bean and whole seed)had highest the gel strength with the values of 2.57 and 7.76 N/cm2 respectively. Determination of phenolic found that, the red kidney bean has most (89.28 mg gallic acid equivalent/ mg). The black cowpea revealed the largest amount of flavonoids and anthocyanins, 524.90 mg catechin equivalent/mg and49.20g.cyaniding-3- glucoside / 100g, respectively. In the study on anthocyanin composition using HPLC method, it was found that delphinidinand cyanidinare the major anthocyanin with the content of 64.89 mg/100gand34.40 mg/100g, respectively. The determination of antioxidant activity by DPPH radical scavenging activity indicatedthat raw beans had highest antioxidant activity. The black and white cowpea hadhighest value of activity (1.01 VEC /g).For cooked beans, red bean and brown bean had strongest antioxidant activity (0.05 VEC/g) whereas the black bean was lowest(0.02 VEC/g). The boiling water of each bean was also evaluated for antioxidant activity. The results showed thatboiling water obtained from black bean had highest antioxidant activity (0.08 VEC/g). The analysis of antioxidant activity by Ferric reducing antioxidant power (FRAP) and total antioxidant activity were also found that raw bean seedsindicated the strongest antioxidant activity which the highest activity was found in red bean (15.98 VEC/g, FRAP) and black bean 2.95 VEC/g, Total antioxidant activity) whilst the lowest antioxidant activity was observed in white cowpea. The study onpreparation of protein concentrate from cowpea was carried out using three different methods including (1) precipitation of proteins by lowering pH, (2) ammonium sulfate , and (3) ammonium sulfate combined with hydrochloric acid. The chemical compositions and functional properties of cowpea protein concentrate were evaluated. The results showed that the preparation with the pH adjustment gave the maximum yield with 16.92%; followed by the precipitation of proteins with ammonium sulfate with hydrochloric acid (5.12%) whereas the precipitation with ammonium sulfate yieldedlowest amount (9.82%).The protein concentrate prepared by adjusting the pH had the highest protein content of 85.85 % , followed by protein concentrate precipitated with ammonium sulfate combined with the hydrochloric acid, protein concentrate precipitated with ammonium sulfate; 74.36 % and 68.28 %, respectively.For the determination of total free amino acid (TFAA) content, the highest TFAA was found in the protein concentrates prepared by adjusting pH (37.80%) , followed by protein concentrateprepared by ammonium sulfate in combination with hydrochloric acid . Protein concentration obtained by adjusting the pH had functional properties superior to those obtained from other extraction methods. The study on solubility of nitrogen, protein concentratefrom adjusting the pH had highest solubility of 64.39 %. The ability to absorb oil washighest of 26.5g/g protein and foam ability of 87.66%. The emulsion ability and stability was also highest in protein concentrate from pH adjustment(80.22 % and 66.88 %, respectively) and the gel ability was 14% whereas gelation ability of protein concentrates obtained by other method were about 16%. For the study on utilization of cowpea flour for cookie making, the black cowpea flour was selected as it contained high RS and was commercially available. Five formulas of cookies were made by replacing wheat flour for 0, 10, 20, 30 and40%. The cookie obtained was evaluated for sensory acceptability, RS content, and bioactive content. The basic formula (made from wheat flour) gained the highest score, followed by the cookie replacing with 20% and 30% of cowpea flour. The basic formula and formula supplemented with cowpea flour to 20 and 30% had similar moisture and ash contents highest in basic formula (2.36%and 9.82%respectively). Fat and fiber contents highest in formula supplemented with cowpea flour 30% and protein content (2.75 to 3.12%), while the concentration of resistant starch was increased significantly (p ? 0.05) when the degree of replacing (cowpea flour) was increased. The anthocyanins and phenolic compounds in cookies also increased (p ? 0.05) when the level of substitution increased. The wheat cookies had the highest hardness (5.18 kg) and b* color (+22.85), while on the cookie obtained from cowpea flour (30%) had softer texture, but darker in L* value (66.35) and a * value (+8.32). The study on chemical compositions, physical properties, and sensory evaluation of low carbohydrate cookies usingprotein concentrateprepared from black cowpea flour by substitute wheat flour for 10, 20, 30, 40, and 50% (with the ratio of 90:10, 80:20, 70:30 , 60:40 and 50:50; wheat flour to cowpea flour). The study found that the chemical compositions of cowpea protein concentrate cookieshad moisture content between 4.04 to 4.36 %,ash content was between 2.34 to 2.98 %. When the level of protein concentrate was increased, the amount of fat and carbohydrates of cookies were decline. The fat content ranged from 18.25 to 20.27% and the carbohydrate content varied between 29.34 to 34.54%.The protein concentration of the cowpea was able to reduce the amount of carbohydrate from a control formula, approximately 43.89 to 52.34 %, and the energy was reduced to 117.36 - 138.16 Kcal per 100 grams. The highest reduction was found in the ration of 90:10 (52.34%, reduction). The protein concentrate couldincrease protein content to 35.25 to 43.03 %.The study on analysis of the physical properties including hardness, color, width, length, and height of a cookie found that the formula with the ratio 50:50 gave the highest brightness (6.42). The high replacing degree was likely lead to a more hardness cookies. The cookie had hardness between 3.24 to 6.95 N. The results of sensory evaluation for color, odor, taste, texture and overall liking scores have been found that formula 50:50 gained the highest in all aspects. The production of cowpea crackers was developedby adjusting the mixture of cowpea flour with corn starch and cassava flour. Then the chemical compositionsand physicochemical properties blended flour were determined and used for making crackers. Black cowpea flour, corn starch, and cassava flour in different ratioswere prepared and studied.Chemical analysis showed that cowpea flour increase the content of protein, fat, sucrose andanthocyanins. By the black cowpea flour ratio 100:0 contained highest level of protein, fat and anthocyanins (23.97%, 1.46% , and 0.29 mg/100g dry weight , respectively). When the flour blended was used to prepare crackers, it was found that the best ratio is 50 black cowpea flour : rice flour 25 and 25 to the tapioca Flour. It gave the brightness L * color values of 66.52, b * color values of 22.47. The sensory evaluation for color, flavor, texture and overall liking . The highest cowpea flour 50: 25 corn starch: starch 25 scored highest in comparison to the other formulas. In terms of the color, flavor, color, texture, and overall liking scores were 6.36, 6.00, 6.96, 8.10, and 7.03, respectively, from the results of sensory evaluation showed that when adding black cowpea flour more, the smell and the color of the cracker was reduced. |
