Impact of Processing on Retention of Beta Carotene of Sweet Potatoes

The study was carried out to evaluate the impact of processing on retention of beta-carotene of sweet potatoes. Eight cultivars of sweet potatoes were used in the study; among which four cultivars were of orange-fleshed varieties viz. ‘CIP 440012’, ‘CIP 440015’, ‘CIP 440267’ & ‘CIP 440021’, and four cultivars were of white fleshed varieties viz. Lamatar White, Balewa Red, Sangachowk Red and Barbote White. The proximate composition and micronutrient composition of eight cultivars of raw sweet potatoes were determined. The carotene content of sweet potato cultivars was also calculated. Finally, the retention of carotene content in sweet potato cultivates under various processing methods (viz. boiling for 30 minutes at 100°C, baking in a microwave oven at 200°C for 30 minutes and drying in a cabinet dryer for 12 hours at 60°C) was observed. The orange fleshed varieties (CIP cultivars) had the greater proximate composition than the white fleshed varieties (local cultivars). The micronutrient composition of orange fleshed sweet potatoes and white fleshed varieties were similar. But the carotene content of the orange fleshed varieties was greater; ranging from 14.43-22.11 mg/100gm. The white fleshed varieties had a low carotene concentration of 0.70-1.83 mg/100gm. The retention of carotene content was observed higher in the boiling process (79%-89%) followed by baking (56%-78%) and least in drying (44%-67%). Also, the orange fleshed varieties had a better retention capability than white fleshed varieties in all the processing methods. Thus, orange fleshed sweet potatoes had a better nutrient profile with higher retention capabilities.

Preparation and Quality Evaluation of Mango based Whey Beverage

This study aims to develop a beverage incorporating whey and mango pulp. Beverage was prepared by blending whey and mango pulp in a ratio of 59.9:30, 64.9:2, 69.9:20 and 74.9:15 (with 10% sugar and 0.1% CMC at 0.3% acidity level). Among the treatments, best formulation of the beverage (based on sensory property) was found to be the whey and mango pulp ratio of 69.9:20 with 10% sugar and 0.1% CMC.

Effect of Type of Sugar and Dough Relaxation Time on the Shape Characteristics of Biscuits

This study was aimed to evaluate the effect of type of sugars namely dextrose, sucrose, sucrose-invert syrup mix, invert syrup and honey, and dough relaxation time of 15, 40, and 65 min. on the shape characteristics viz. width, thickness, spread ratio, and an expansion ratio of biscuits. The type of sugars significantly affected (p<0.05) all shape characteristics, while the dough relaxation only affected those of crystal sugars (sucrose and dextrose). High dough relaxation time enhanced the width of sucrose biscuits without significantly affecting (p>0.05) their thickness. In contrast, the thickness of dextrose biscuits decreased with increasing relaxation time. Liquid sugars (invert syrup and honey) enhanced the width of biscuits; the former enhancing the thickness as well. The study also demonstrated that a high spread ratio may also be associated with a low expansion ratio. Hence, both the spread ratio and expansion ratio must be considered when discussing the shape characteristics of biscuits with different ingredients.

Production of Rice Based Alcoholic Beverages and their Quality Evaluation

Murcha is a traditional starter culture used for the production of alcoholic beverages in Nepal. The present study was conducted to compare and characterize rice-based alcoholic beverages prepared from varieties of rice as well as starter culture. Optimization of the production was performed using three criteria (pH, temperature, and Brix). Four different rice varieties (marsi/ red rice (RR), black rice, taichin, and khumal-4) and four different cultures (ATCC 18824, murcha, yeast isolated from murcha, and commercial wine yeast) were used to prepare rice-based alcoholic beverages under optimized condition. The highest acidity was found in black rice (BR) fermented by murcha (2.0±0.0 %). The highest alcohol was found in the taichin rice fermented by isolated yeast (23.38±0.00 %) and wine yeast (23.38±0.00 %). The highest antioxidant was found in BR fermented by wine yeast (WY) (68±0.002%). The highest phenolic content and reducing sugar was found in BR fermented by ATCC (103.2±0.02mg/l) and (1064±0.03µg/ml) respectively. The study showed different cultures and rice variation gives beverages with different characteristics. The results were subjected to statistical analysis. The result was found to be significant (p <0 .05).

Optimization of Crude Papaya (Carica papaya) Protease in Soft-Unripened Cheese Preparation

The use of plant protease instead of chymosin for producing cheese has become a trend which is aimed at lacto-vegetarian consumers and religion based ecological markets. In this context, the present investigation was carried out in order to utilize milk clotting enzyme from Papaya (Carica papaya). Numerical optimization study revealed that maximum milk clotting activity was achieved at pH 6.5, temperature 70℃ and enzyme concentration 1 g/1000 ml milk using papaya protease as coagulant. Protein, ash and calcium showed no significant (p>0.05) difference among the cheeses made using different coagulants. However, significantly (p<0.05) higher levels of moisture and ash, and lower levels of fat were observed in the cheese produced by papaya protease compared to that made using rennet. Papaya protease significantly enhanced the spreadability of cheese while the other sensory properties were similar to the control except aftertaste. The results revealed that the papaya latex as crude papaya protease may have potential application for the manufacture of soft-unripened cheese and further could be utilized as a milk coagulant in cheese making.

Socio-demographic characteristics and Iodine status of the school-going children of Suryodaya Municipality, Ilam

Iodine deficiency disorder (IDD) is a major micronutrient deficiency problem in Nepal. This study was conducted with objective to measure the Urinary iodine excretion (UIE) and attempts were made to relate urinary iodine with salt use and other sociodemographic variables of household of primary school children of Suryodaya municipality of Ilam district of Nepal. A community based cross section study was conducted in two schools of study area selected randomly (lottery method). A total of 202 school children of 6-12 years were recruited for the study to collect urine and salt samples for urine iodine content (UIC) and salt iodine content (SIC) measurement respectively and detail information of study population was achieved from their household. UIC was measured by ammonium persulphate digestion microplate (APDM) method and SIC was estimated by rapid test kit (RTK). Data were expressed in frequency, mean±SD and median (IQR) according to the nature of data. Chi-square test, Mann-Whitney U test and Kruskal-Wallis test were used to test the significance considering p≤0.05 at 95% confidence interval. It was found that Median UIC of the study population was 152.14 µg/L. Overall; it was found that 30.7% children had urine iodine level less than the normal WHO levels. The availability of adequately iodized salt was 93.1% as measured by RTK. There was statically significant association between consumed salt iodine content and urine iodine excretion level (P < 0.05).

Study on Post Harvest Losses in Potato in Different Storage Conditions

The study aimed to conduct a comparative study of three most common potato storage conditions (in-house store, in-basket store and cold store) and to find the most suitable storage condition for farmers. The experimental work involved post-harvest loss assessment and study of pattern of respiratory and reducing sugar level for sixty days storage period. Total loss was lowest (4.38%) for cold stored potatoes and highest (13.04%) for in-house stored potatoes. Reducing sugar accumulation was least (0.65%) and remained almost constant throughout study period for in-house stored potatoes. Reducing sugar accumulation gradually increased and was maximum (1.04%) for cold stored potatoes. Respiratory rate was least in cold stored potatoes which gradually decreased and reached 3.17mg CO2/kg/hr at the end of sixty days storage. Respiratory rate was maximum for in-basket stored potatoes which reached up to 6.55 mg CO2/kg/hr at the end of storage. Storage loss and respiratory rate are minimum for cold stored potatoes but showed high sugar accumulation. In-house storage do not suffer from excessive sugar accumulation but storage loss is maximum of all. In case of in-basket storage, besides being cheap and feasible, there is no problem of sugar accumulation and storage losses was also significantly lower than in-house storage.

Purification and Characterization of a Noble Thermostable Alpha-amylase from Anoxybacillus tengchongensis RA1-2-1 Isolated from Geothermal Spring of Nepal

A thermophilic amylolytic strain, Anoxybacillus tengchongensis RA1-2-1 was isolated from geothermal spring of Rasuwagadi district of Nepal. The BLAST alignment of the 16s rRNA sequence revealed 99.3% similarity with the type strain Anoxybacillus tengchongensis T-11. The morphological, physiological and biochemical properties were similar to the type strain. The enzyme from the strain was purified to 40-fold purification by DEAE-cellulose ion exchange chromatography. The Km value of the enzyme was 0.68±0.05 mg/ml. The optimum pH and temperature were 7.0 and 70 °C. SDS-PAGE analysis showed a single band at 69 kDa. The half-life of the enzyme at 70°C and 80°C were 85.01min and 51.96 min respectively. TLC analysis of the hydrolysis product showed that the enzyme is maltogenic amylase. The calcium independent enzyme was completely inhibited by Hg2+ but showed inhibitory effect in the range of 100 %-30 % in the presence of other salts at 1-10 mM concentrations.

Microbial Quality of Chhoyla and Kachela: Traditional Newari Meat Products

Chhoyla and Kachela are indigenous and popular meat dishes in the Newar community that are widely consumed in Kathmandu valley. The present study was carried out to investigate the microbial quality of Chhoyla and Kachela from different parts of the valley. The mean total aerobic plate count of Chhoyla and Kachela ranged up to 6.38 and 6.54 log10 cfu/g respectively. The mean total coliform count of Chhoyla and Kachela ranged up to 5.25 and 5.82 log10 cfu/g respectively. Coliform (93%), Staphylococcus aureus (75%), Salmonella Typhi (12%), Salmonella Paratyphi A (5%) and Shigella spp (3%) were isolated from Chhoyla. Likewise, bacteria isolated from Kachela were coliforms (97%), Staphylococcus aureus (86.66%), Salmonella Typhi (15%), Salmonella Paratyphi A (8%) and Shigella spp (7%). High microbial load and the potent human pathogens isolated from these meat products indicate potential risk of food borne diseases.

Detection of Genistein in Soy Protein Isolate and Soymilk Powder by Spectrophotometric and Chromatographic Method

Genistein proposed as a treatment for osteoporosis for postmenopausal women, elderly men, lowering cardiovascular disease and reduces hormone dependent cancers. Genistein also exerted inhibitory effect on lipid peroxidation induced in vitro by pro-oxidant agents on model and natural membranes on cultured cells and on low density lipoprotein. Genistein detection in soy products is very much important for Food Scientist. Gensitein can be detected by UV-Visible spectrophotometric and HPLC method. This study focused on the detection of genistein by HPLC and spectrophotometric methods. Genistein content of both soy protein isolate (SPI) and spray dried soy milk powder (SMP) was determined by spectrophotometry (93.12±1.15 and 74.78±0.75 mg/100g, respectively) were slightly higher but not significantly differ than HPLC analysis (89.67±5.16 and 72.34±0.27 mg/100g, respectively). This study suggested that genistein and its glycoside could be detected by spectrophotometric methods with high accuracy.