Effect of Processing on Resistant Starch Formation in Food: A Review
Resistant starch (RS) is the fraction of starch that remains undigested in small intestine in human and metabolized in large intestine that has potential to improve human health. Processing operations tend to destroy the structure of native starch granule forming retrograded starch (RS3) which is manifested by the change in conformation of starch structure such as crystallinity; thermal properties; morphology; viscosity and other physico-chemical properties. To improve the RS content in foods, it is imperative to know the effect of processing on the transformation of starch properties leading to altered enzyme resistance of native starch. This paper reviews the starch structure and effects of various processing techniques on the formation of enzyme resistant starch in foods.
Key words: Resistant starch, Retrogradation; Structure; Processing
Journal of Food Science & Technology Nepal Volume 4, September, 2008 Page: 1-11
Inhibition of Microbes in the Presence of Lactoferrin and Its Derivatives
Lactoferrin plays an important role in the antimicrobial defense through iron binding, lipopolysaccharide binding and immunomodulation and it appears to have a wide variety of uses in biological systems and is considered a first line immune defense in the human body. Though a natural component of cows and human mother's milk, lactoferrin is found throughout the human body and occurs in all secretions that bathe mucous membranes such as saliva, tears bronchial and nasal secretions, hepatic bile, pancreatic fluids, and is an essential factor in the immune response. Research using various animal models has found the ingestion of lactoferrin to have direct protective effects on the regulation and modulation of the immune system. Wide spectrums of functions are ascribed to lactoferrin. Lactoferrin has also been found to both directly and indirectly inhibit several viruses that cause diseases in humans. It directly inhibits viruses by binding to receptor sites, thus preventing the virus from infecting healthy cells. In addition, lactoferrin indirectly kills or inhibits viruses by augmenting the systemic immune response to a viral invasion. Many researchers studied the antifungal effect of lactoferrin via its iron binding capacity and showed potent inhibitory effect on fungal growth.
Key Words: Lactoferrin; Derivatives; Antibacterial; Antiviral; Antifungus
Journal of Food Science & Technology Nepal Volume 4, September, 2008 Page: 12-17
Genetically Modified Organism (GMO) and Its Detection Method
Gyan Sundar Sahukhal, Bina Laxmi Jayana, Nirmal Dhungana, Nawa Raj Dahal, Ganesh Dawadi, Shova Shrestha, Vishwanath Prasad Agrawal
Genetically modified (GM) crops currently account for 29% of crop production worldwide. Despite a lack of regulations to provide for food labelling that allows for consumer preference, many products carry negative or positive labels with regard to genetic modification. Regulatory demands of labelling and traceability of GMOs in the food chain need suitable sampling protocols and analytical methods. At present, two main techniques, the DNA-based polymerase chain reaction (PCR) and the protein-based enzyme-linked immunosorbent assay (ELISA) are most widely used, although new technologies, such as microarrays, have been also developed. The main objective of this review paper is to assess the detection methods both protein based and PCR based as described by different researchers, which represents the state-of-the-art technique for GMO detection in food.
Key words: GMO; Beneficial Aspects; Harmful Aspects; Detection Strategy
Journal of Food Science & Technology Nepal Volume 4, September, 2008, Page: 18-22
A Survey Study on Technology of Sel-roti: A Traditional Food of Nepal
Surendra Bahadur Katawal, Dilip Subba
Sel-roti is a popular rice-based, sweet, puffed, spongy, deep-fat fried, ring-shaped doughnut like indigenous food product of Nepal. A survey study was carried out to document the traditional practice of sel-roti preparation. Altogether 126 respondents belonging to different ethnicity, religion, age and sex groups of Eastern and Central regions were involved in this study. Definition and origin, ingredients and functions, recipe, preparation procedure and method of preparation, utensils, cooking fuel, desirable quality characteristics and factors influencing them, production and marketing, occasions of use and storage of sel-roti have been documented in this article.
Key words: Recipe; Equipment; Method of Preparation; Sel-roti;Sensory quality; Nepal
Journal of Food Science and Technology Nepal Volume 4, September, 2008 Page: 23-30
Assessment of Certain Pesticide Residues in Nepalese Tea
Pramod Koirala, Nawa Raj Dahal, Jiwan Prava Lama, Uttam kumar Bhattarai
Nepalese tea, due to its unique flavor and aroma, is popular in Nepal and in international market. A field survey study on the use of pesticides during tea cultivation was carried out, tea samples were collected and laboratory analysis was done on certain pesticide residues. The result revealed that eighteen types of pesticides were commonly used during tea cultivation. Laboratory analysis of sixteen types of pesticides showed that pesticide residue in Nepalese tea was below the MRLs established by CODEX, India, Japan and EU countries.
Key words: Tea, Insects and pests; Pesticide residues; MRL; Nepal
Journal of Food Science and Technology Nepal Volume 4, September, 2008, Page: 31-33
A Case Control Study on Risk Factors Associated with Malnutrition in Dolpa District of Nepal
Malnutrition remains a serious obstacle to child survival, growth and development in Nepal. The most common forms are protein-energy malnutrition (PEM) and micronutrient deficiency states (iodine, iron and vitamin A deficiency). A case-control study design was used. Case were defined as malnutrition (Weight-for- Age Z- score <- 1.96 SD). Controls were defined as neighborhood population of same age group selected randomly from the same VDC. A total of 105 cases 112 controls were selected. All parents of cases and controls were interviewed face-to-face using a semi-structure questionnaire after anthropometric measurement of children. In addition to general background information, respondents were asked questions about suspected risk factors. Among the risk factors; immunization, age, educational status of mother, Iron tablet during pregnancy and antenatal checkup shows a significant risk association with malnutrition. Immunization (OR = 2.18), age of children (OR = 1.023) and education of mother (OR = 2.134) as well as positive risk association between malnutrition and iron supplementation during pregnancy (OR=1.993) and ANC (OR = 2.167). However, vitamin A supplementation, de-worming tablets, number of family members in the family and working hours of mother does not reach statistical significance. Socio-demographic factors: low maternal education, immunization and poor feeding practices for children are affecting children's health regarding malnutrition.
Key words: Malnutrition; Z-score; Education of mother; Antenatal check-up (ANC)
Journal of Food Science and Technology Nepal Volume 4, September, 2008, Page: 34-37
Nutritional and Functional Properties of Kashk: Fermented Sheep Milk
The objective of the study was to determine the nutritional and functional properties of ‘Kashk' by standard techniques. "Kashk" is fermented and dried sheep milk used in Iranian diets. The nutritional composition of Kashk per 100 g was as follows: moisture - 13.3g; total ash - 12.75g; protein - 60.0g; fat - 5.2g; iron - 0.55mg; phosphorus - 3.5g and calcium - 2.4g. The in vitro digestibility of protein was found to be 71%. Bulk density was 71.4g/100ml and water and fat absorption capacities were 190 and 130 ml/100g respectively. Emulsification activity and emulsion stability were 57% and 53% respectively. Nitrogen solubility indicated pH 5.0 to be the isoelectric pH. The protein quality of Kashk was determined by animal assays. The protein efficiency ratio was 2.5, net protein ratio (NPR) and relative NPR were 3.7 and 2.92 respectively and relative nitrogen utilization was found to be 80. Kashk is a nutritious food adjunct and can be recommended for use in diets of children, pregnant and lactating women due to high quality proteins and high calcium.
Key words: Fermentation; Digestibility; Protein efficiency ratio; Net protein ratio; Relative nitrogen utilization
Journal of Food Science and Technology Nepal Volume 4, September, 2008 Page: 38-42
Polyphenols and Antioxidants in Masyaura
Masyaura, a legume based traditional fermented food product of Nepal, prepared from blackgram dhal and colocosia tuber by different fermentation methods were evaluated for polyphenol and antioxidant characteristics. Total polyphenol content of Masyaura ranged from 235 to 351 mg/100g on dry matter. Blackgram dhal and colocosia tuber showed polyphenol content higher (P=0.05) as compared to Masyaura showing the value of 838 and 826 mg/100g respectively. Tannin content in Masyaura was found in the range of 101 to 131 mg/100g. Total reactive antioxidant potential (TRAP) value in Masyaura was found in the range of 7.6 to 10.6 mM as ascorbate on dry matter; while blackgram dhal and colocosia tuber showed TRAP value of 9.9 and 23.4 respectively. Antioxidant property was found to be higher (P=0.05) in stored Masyaura as compared to the fresh one.
Key words: Masyaura; Polyphenol content; TRAP value; Fermented food; Nepal
Journal of Food Science and Technology Nepal Volume 4, September, 2008, Page: 43-46
Study on Brewing Quality of Naked Barley (Hodeum Vulgare L.)
Dev Raj Acharya, Dhan Bahadur Karki
Proximate composition of naked barley (Hordeum Vulgare L.) and chemical characteristics of naked barley malt were analyzed. Chemical and sensorial quality of beers made from naked barley and commercial barley malts were compared. Moisture, ash, crude fat, crude protein, total carbohydrate, crude fiber and starch contents of naked barley were 8%, 1.28%, 2.82%, 11.88%, 76.03%, 1.41%, 68.53% (db) respectively. Naked barley germinated for 24 hrs had the highest amylase activity (47.13 units/100g dm). Chemical composition comparison between naked barley malt and commercial malt revealed that except percentage extract and reducing sugar other parameter viz. aroma, pH, moisture, starch, ash, specific gravity of extract, protein and amylase activity were not significantly different (p>0.05), but saccharification time, filtration rate and clarity of the extract was poor in naked barley malt compared to commercial malt. Results of chemical analysis of beers prepared from naked barley malt and commercial malt showed that pH, TSS, titrable acidity, fixed acidity, volatile acidity, esters, real extract, apparent extract, real degree of fermentation, reducing sugar, dextrin, ash and protein contents were not significantly different whereas original extract and alcohol contents were significantly higher in commercial malt beer. Sensory evaluation indicated that except mouthfeel other parameters such as appearance and clarity, color and flavor scores were higher in beer made from commercial malt than that of naked barley malt. It can be concluded that naked barley malt of satisfactory brewing quality could be prepared by following standard malting procedure adopted for barley malt.
Key words: Naked barley; malt; beer; chemical characteristics; sensory quality
Journal of Food Science and Technology Nepal Volume 4, September, 2008, Page: 47-51
Antibiotic Resistant Escherichia coli in Meat Samples from Kathmandu Valley
Vijay Singh Chhetri, Indra Bahadur Pachhai, Pramod poudel, Huma Bokkhim, Yug Nath Dabadi
The present study was carried out on 39 meat samples (18 chickens, 12 buffs and 9 pork samples) with an objective to determine the occurrence of antibiotic-resistant E. coli. Meat samples were collected from Kathmandu valley. Selective cultures and disc-diffusion assays were performed for
isolation and characterization of antibiotic resistant E. coli. Occurrence of E. coli was observed in 100% meat samples. Higher percentage (34%), of the isolates were found to be resistance to Ampicillin and 8% isolates exhibited resistance to more than one antibiotics (Cephalexin, Nalidixic acid, and Gentamycin). None of the isolates were resistance to Tetracycline. The result revealed that meat sold in the Kathmandu valley may serve as an important vehicle for community-wide dissemination of antibiotic- resistant E. coli which may represent a newly recognized group of medically significant food borne pathogens.
Key words: Antibiotic resistant; E. coli; Chicken; Buff; Pork; Kathmandu valley
Journal of Food Science and Technology Nepal Volume 4, September, 2008, Page: 52-53
Socio-Demographic and Nutritional Status of Pregnant Mothers Attending Maternity Centre of Dhaka, Bangladesh
Birendra Kumar Yadav, Ahsan Habib, Selina Ahmed
This cross- sectional study was conducted among the women at Azimpur maternity center, Dhaka with the objective to find out socio-demographic and nutritional status. Total number of respondents was 201. The mean age of the respondents was found to be 23.4± 4.2 years and mean age at marriage was found to be 18.9±3.3 years. Out of 201, 97% of the respondents were housewives and most of them lived in urban areas (66.2%). Almost half of the respondents (50.2%) were educated up to secondary level. About 2/3rd of the total respondents (66.7%) received antenatal checkup (ANC) for more than 3 times. Majority (87%) of the respondents maintained a gap of 3 or more years between two successive pregnancies. Nutritional status of the mothers in terms of body mass index (BMI) showed that more than half (51.7%) of the mothers were normal (BMI of 19.8-26 kg/m2), 46.3% were overweight (BMI >26 kg/m2) and only 2% were under weight (BMI <19.8-26 kg/m2). Majority (95%) of the mothers had mean arm circumference (MAC) >22cm.
Key words: Socio-demography; Maternity; ANC; BMI; MAC; Dhaka
Journal of Food Science and Technology Nepal Volume 4, September, 2008, Page: 54-56
Assessment of Aflatoxin B1 Level in Chilli, Maize and Groundnut Samples from Kathmandu Valley
Devaki Nandan Gautam, Rita Bhatta, Megh Raj Bhandary
Altogether 360 samples of chilli, maize and groundnut (120 from each commodity) were collected from Kathmandu Valley in four different seasons from April 2007 to January 2008, for the determination of Aflatoxin B1 (AFB1). TLC Method was used for estimation of AFB1). Out of
360 samples, 88 (26 chilli, 30 maize and 32 groundnut) samples were found to be contaminated with AFB1 at the level of more than 10 µg/kg and average concentration of AFB1 in three commodities was found to be 50.8 µg/kg. Among the contaminated samples, chilli showed least amount of AFB1 i.e. 34.87 µg/kg on average; maize showed 50.17 µg/kg and ground nut showed the highest amount i.e.64.23 µg/kg of AFB1 contamination. Among the analyzed samples, 14 chilli, 18 maize and 24 ground nut were found to be contaminated with the AFB1 at more than 20 µg/kg (i.e. recommended maximum permissible level in Nepal) .Based on the seasonal variations, maximum number (26) and maximum amount (64.99 µg/kg) of contamination was found in April and January respectively among three commodities.
Key words: AFB1; Contamination; Chilli; Maize; Groundnut; Kathmandu valley
Journal of Food Science and Technology Nepal Volume 4, September, 2008 Page: 57-60
Antidiabetic Activity of Laligurans (Rhododendron arboreum Sm.) Flower
Anti-diabetic activity was examined in Laligurans (Rhododendron arboreum Sm) flower and active compounds were isolated from it. Aqueous methanolic extract of the flower of Laligurans was found to show inhibitory activity on the rat intestinal α-glucosidase. Both the water-soluble and ethyl acetate-soluble portions from the aqueous methanolic extract showed inhibitory activities on α-glucosidase, demonstrating higher activity by the ethyl acetate-soluble portion. From the ethyl acetate-soluble portion, α-glucosidase inhibitor quercetin-3-O-β-D-galactopyranoside (hyperin) was isolated through enzyme-assay guided separation. The isolated compound showed a dose dependent α-glucosidase inhibitory activity with IC50 values of 1.66 mM and 0.76 mM for sucrase and maltase, respectively. This study revealed that Laligurans flower contains antidiabetic potential which property might be helpful to develop medicinal preparations, nutraceutical or functional food for diabetes and its complications.
Key words: Laligurans; Rhododendron arboreum; Medicinal herb; a-Glucosidase inhibitor; Diabetes; Nepal
Journal of Food Science and Technology Nepal Volume 4, September, 2008, Page: 61-63
Proteolytic Effect of Starter Cultures on Dry Fermented Chinese-Style Sausage
Krishna Prasad Rai, Ashok Kumar Shrestha, Wensui Xia
The proteolytic effect of three different starter cultures (Lactobm: acillus casei subsp.casei-1.001, Pediococcus pentosaceus-ATCC 33316 and Staphylococcus xylosus-12) on dry fermented Chinese-style sausages has been investigated. The increment in non-protein nitrogen (NPN) was significantly highest (p < 0.05) (6.8mg/g dm) in sausage inoculated with S. xylosus-12, while lowest (4.8mg/g dm) in control. Moreover, free amino acids such as Glu, Gly, Thr, Arg, Val, Trp, Phe, Leu, Lys and Pro were predominantly found (above 30mg/100g dm), summing up over 80% of the total. The sausage added with starter Sx-12 showed the highest content of total free amino acid (1287.9 mg/100g dm) and lowest in control. The essential free amino acids were increased approximately by 2.5 times in ripened products as compared to initial minced mix. SDS-PAGE showed that the intensity of myosin heavy chain (HMC) in myofibrillar muscle became thinner due to proteolysis action of starter cultures and producing a lower molecular weight protein (~116kDa). Likewise, the actin degradation was observed more intensive in starter added sausages. Other protein bands like troponin-T (37kDa), myosin light chain-1 (25kDa), myosin light chain-2 (18kDa), and myosin light chain-3 (15kDa) noticeably degraded during ripening of products inoculated with starter cultures. In other hand, the protein bands with molecular weight ~26, 43, 50, 97, and 150 kDa have been totally disappeared after ripening process, while no effect on protein band particularly with molecular weight ~40kDa was observed, meanwhile the intensity of polypeptide with a molecular weight of ~13, and 21kDa were increased in ripening due to degradation of higher polypeptide bands caused by bacterial proteolysis and protein denaturation due to high acid or salt concentration in products. Therefore, the starter cultures S. xylosus-12 and P. pentosaceus- ATCC 33316 were more capable in protein degradation forming several free amino acids and lower molecular weight peptides during fermentation and ripening of dry fermented Chinese-style sausage, which could improve the flavour and textural properties of such meat products.
Key words: Starter culture; Dry fermented Chinese-style sausage; Proteolysis; Amino acids
Journal of Food Science and Technology Nepal Volume 4, September, 2008, Page: 64-69
Storage Stability of Fermented Finger Millet (Eleusine coracana) Packaged in PVC Container under Ambient Conditions
Dhan Bahadur Karki, Ganga Prasad Kharel
Effects of PVC container packaging on the chemical and sensory quality of fermented millet under ambient condition were studied. Finger millet was fermented for 15 days at room temperature (25 ±2ºC) using defined fermentation starter, packaged in PVC container and stored at room temperature for 90 days and analyzed for chemical and sensory characteristics as compared to the control (Stored at -300ºC, 0 day). Moisture content; total, fixed and volatile acidities and total sugar did not differ while alcohol content decreased significantly (p < 0.05) in room temperature
stored sample (14.4 % v/m) compared to control (13.1% v/m). A significant increase in total soluble solids, reducing sugar, total aldehydes and ester contents occurred in 90 days stored sample. Sensory evaluation revealed that remarkable improvement on color, taste and smell of the millet and occurred in room temperature stored millet than that of control counterpart. Hence, PVC could be a promising packaging container in extending the shelf-life of fermented millet.
Key words: Fermented millet; PVC container; Storage stability; Chemical and Sensory quality
Journal of Food Science and Technology Nepal Volume 4, September, 2008, Page: 70-71
Production of Probiotic Soy-Yoghurt by Inoculating Lactic Acid Bacteria isolated from Yoghurt Samples from Kathmandu Valley
Pramod Poudel, Tika Bahadur Karki
Lactic acid bacteria were isolated from six indigenous yoghurt samples of Kathmandu valley. The most predominant lactic floras were Lactobacillus sps, Streptococcus sps and Pediococcus sps. These lactic floras were screened on the basis of soy-lactic fermentation. The best screened lactic acid bacteria were identified as Lactobacillus casei (LJ3), and Streptococcus thermophilus (L17) on the basis of sugar fermentation, growth pattern at different pH and salt concentration. These strains were further used for the development of probiotic soy-yoghurt. Viable count of 108 CFU/ml and sustainability of gastric pH upto 48 hours of fermentation showed the probiotic nature of soy-yoghurt prepared by inoculating Lactobacillus Casei and Streptococcus thermophilus isolated from yoghurt samples collected in Kathmandu valley.
Key words: Probiotics, Soy-yoghurt, Lactic acid bacteria, Kathmandu Valley
Journal of Food Science and Technology Nepal Volume 4, September, 2008, Page: 72-73
Screening of Cry-Type Genes among Bacillus thuringiensis Isolated from Soil Samples in Phereche and Sagarmatha National Park of Mount Everest Base Camp Region by PCR
Gyan Sundar Sahukhal, Bina Laxmi Jayana, Upendra Thapa Shrestha, Eitan Ben Dov, Viswa Nath Prasad Agrawal
The PCR method was performed to rapidly identify and classify Bacillus thuringiensis strains containing cry (crystal protein) genes toxic to species of Lepidoptera, Coleoptera, and Diptera using seven sets of universal primers namely Un-1, Un-2, Un-3, Un-4, Un-5, Un-7/8 and Un-9. Two sets of primers Un-cyt1 and Un-cyt-2 were also used to detect cytolytic genes. The technique enriches current strategies and simplifies the initial stages of large-scale screening of cry genes by pinpointing isolates that contain specific genes or unique combinations of interest with potential
insecticidal activities, thus facilitating subsequent toxicity assays. Sixteen B. thuringiensis isolates were studied and the occurrences of cry1-type genes were found highest (68.75%) among the isolates, followed by cry7/8 and cry2 (56.25% and 50% respectively), cry4 and cry-9 (12.50% each) and finally cry5 among 6.25% isolates. Cry3 type genes were not detected among any isolates. Cyt2 types genes were detected among 12.50% isolates but cyt1 type genes were not detected in any of the isolates.
Key words:Bacillus thuringiensis; PCR, Soil; Everest Region
Journal of Food Science and Technology Nepal Volume 4, September, 2008, Page: 74-77
UNITED NATIONS Economic and Social Council COMMISSION ON HUMAN RIGHTSFifty-fifth sessionItem 12 (a) of the provisional agendaINTEGRATION OF THE HUMAN RIGHTS OF WOMENAND THE GENDER PERSPECTIVEReport of the Special Rapporteur on violence against women, itscausesand consequences, Ms. Radhika Coomaraswamy, in accordancewith Commission on Human Rights resolution 1997/44Policies and practices