Proximate, functional and pasting properties of a new variety of sweet potato, VitAto, flour, known for its high vitamin A contents, were compared with two other commercial sweet potatoes, Bukit Naga and Okinawan, flour available in Malaysia. The recoveries of each sweet potato from milling were not significantly different at about 20% but in proximate analysis, the VitAto presented the highest protein (5.7%) and dietary fiber (14.8%) contents with more energy 399.6 kcal/100 g produced. The VitAto flour has average particle size of 132.04 μm. The pasting temperature of the VitAto flour was 65oC, with highest setback and trough viscosity values of 530.90 and 197.20 mPa.s, respectively. The flour is classified as easy flowing and stable powders. This study provides information which helps in the handling, packing and storage of sweet potato flours. It also shows that the VitAto flour has an array of functional, pasting and proximate properties that can facilitate its uses in many areas with better nutritional properties.
Changes of physico-chemical properties such as size, weight, moisture content, total soluble solid
(TSS), colour, pH, total acidity and sugar content of red seedless watermelon during storage at room temperature (± 28ºC; 70-80% RH) were investigated. The average weight, diameter and length of red seedless watermelon were 5.94 kg, 22.0 cm and 21.8 cm respectively. The length to diameter ratio was 1.02. The statistical analysis indicated that total soluble solids of fruit decreased significantly (p
Guava (Psidium guajava L.) is a rich source of vitamin C (ascorbic acid) having high water
content (above 80%) which makes it extremely perishable, but storage, handling, processing
and transporting becomes difficult due to high moisture content. Therefore, guava needs
dehydration process by upholding its natural colour and minimum ascorbic acid losses. We
have carried out a comprehensive study to examine the influence of different drying treatments;
under direct sunlight, freezing, convection oven (50, 60, 70, 80 and 90°C) and microwave
oven (100, 250, 440, 600 and 1000 watts) on ascorbic acid concentration and colour quality
of guava. The mean values of ascorbic acid concentration of dried guava slices were changed
significantly (P < 0.05) as compared to fresh guava slices. The colour of guava slices became
yellowish with an increase in temperature and power of conventional and microwave ovens,
respectively. We found freeze drying as the best method for the dehydration of guava in terms
of ascorbic acid and natural colour preservation.
The Nigerian hog plum (Spondias mombin) seed kernel was studied for its possible antioxidative
potential and its proximate and nutrient compositions measured. The fruits were
submitted to washing, pulp removal and drying to facilitate fibre separation from the seed
kernel. Seeds were Milled to obtain samples, while analysis was carried out using standard
Association of Analytical Communities (AOAC) methods and phytochemical assays. The seed
kernel contains carbohydrate (40.56%), ash (8.09%), crude fibre (31.86%), moisture content
(8.48%), crude protein (7.73%), crude fat (3.28%), calcium (1317 mg/kg), iron (839.08 mg/
kg), magnesium (494.71 mg/kg), manganese (17.93 mg/kg), zinc (15.27 mg/kg), and copper
(7.68 mg/kg). Phytochemical analyses indicated the presence of tannins (0.06%) and phytate
(0.0022%), but did not indicate the presence of flavonoids, oxalate and saponins. The free
radical scavenging activity against the 2, 2–diphenyl–1–picrylhydrazyl (DPPH) radical
was at the level of 15.09%, while total antioxidant capacity and total phenolic content were
856.7±5.84 mgAAE/100g and 573.32±11.5 mgGAE/100g respectively. The seed kernel of
Spondias mombin is a potential source of nutritious food, good anti-anaemic and anti-diabetic
agent as a result of iron and zinc content, and potential chemo-protective agent with the ability
to offer possible protection against the activities of the toxic Reactive Oxygen Species (ROS)
from the results of total phenolic content, antioxidant and free radical scavenging activities.
This work describes the effects of different cooking temperatures in repetitive cooking-chilling (RCC) process on resistant starch (RS) content in fish crackers prepared in a ratio of 1:1 fish to sago starch formulation. In this work, three sets of four RCC cycles were performed on fish crackers, in which each set was cooked at fixed temperatures of 100, 115 and 121°C, respectively. The chilling temperature was fixed at 4°C in all cases. Subjecting the fish crackers to a higher cooking temperature for up to 4 cycles of RCC can increase the RS content. However, quality degradation was observed in the characteristics of the fish crackers. During the first RCC cycle, cooking at a higher temperature had caused the crackers to crack and burst. Besides, defragmentation to the shape of the fish cracker gels was also observed during the first RCC cycle, coupled with softer texture and high moisture content. When the products were subjected to frying, their linear expansion decreased, the texture became harder and the colour turned darker. This work demonstrated that the application of higher cooking temperature up to 4 RCC cycles was able to enhance the RS content in the fish crackers, but it was less able to attain the product's perfect shape. On the contrary, fish crackers that were exposed to lower cooking temperatures contained lower RS but with less shape damage.
Roasting of whole-kernels is an important step in the production of pistachio paste. The effect of hot air roasting temperatures (90-190°C) and times (5-65 min) on the hardness, moisture content and colour attributes (‘L’, ‘a’ and ‘b’ values and yellowness index) of both whole-kernel and ground-state were investigated using response surface methodology (RSM). Increases in roasting temperature and time caused a decrease in all the responses except for ‘a’ value of ground-state. The interaction and quadratic models sufficiently described the changes in the hardness and colour values, respectively. The result of RSM analysis showed that hardness and colour attributes (‘L’ and ‘b’ values, yellowness index) of kernels and ‘a’ value of ground-state could be used to monitor the roasting quality of whole-kernels. This study showed that the recommended range of roasting temperature and time of whole-kernel for the production of pistachio paste were 130-140°C and 30-40 min, respectively.
The present study was aimed at assessing the effect of solvents on the yield and the color properties of amaranth extract. Two species of amaranth namely Amaranthus gangeticus and Amaranthus blitum were extracted with water, methanol and ethanol. Seven parameters like betacyanin content, total soluble solids, lightness (L*), redness (a*), yellowness (b*), hue angle (h*) and chroma (c*) were analyzed to assess extraction efficiency. Correlation analysis was carried out to assess the linear association among the analytical variables. Principal component analysis was used to establish the relationships between the different analytical variables and to detect the most important factors of variability. Among the two varieties, Amaranthus gangeticus extract contained about two and half time more betacyanin with half of total soluble solids compared to Amaranthus blitum. Water is the best as solvent for extracting betacyanin from Amaranthus gangeticus and ethanol in case of Amaranthus blitum. Among the analytical parameters, a* and c* were perfectly correlated. Three principal components were found among the seven analytical variables accounting 88% of total variability. The first principal components mostly reflected the redness (a*), whereas the second principal components reflected the betacyanin content, total soluble solids and lightness (L* value).
Tamarind and pineapple fruit pulps and powders were assessed based on their physicochemical properties such as crude protein, crude fibre, fat, ash, moisture content, water activity (Aw), particle shape, particle size distribution, and density. Both of the fruit powders were subjected to a similar spray-drying process with the addition of 10% w/v of maltodextrin. The nutritional value in terms of crude protein (0.33 - 0.60%), moisture content (4.80% - 25.31%), crude fiber (16.92 - 79.92%), and fat (0.40 - 0.63%) for both fruit pulp and powders shows a significant difference at p
Viscosity and physical properties of flours and pastas prepared from four cultivars of green bananas (namely Pisang Berangan, Pisang Nangka, Pisang Tanduk, and Pisang Nipah) have been evaluated. The moisture content and water activity of banana flours were found in the range of 7.71%-8.50% wet basis and 0.33-0.37, respectively. The peak viscosity of banana flours were observed in the order of Pisang Tanduk > Pisang Nipah > Pisang Nangka > Pisang Berangan. The water activity and colour of pastas prepared from banana flours were lower and darker compared to wheat pasta. The firmness of banana flour dried pastas were observed significantly higher than wheat pasta, with Pisang Berangan pasta recorded the highest value of 446.53 ± 7.44 g. Among the green banana cultivars, pastas prepared from Pisang Nipah and Pisang Nangka flours are recommended for consumer who is preferred of bright colour and firm texture cooked pastas.