Category Archives: b_original_articles

Anis Surayani Mat Yaacob¹, Nurul Aishah Mazlan¹, Kamaliah Abdul Samad¹, Syed Mohd Saufi¹, Hafizuddin Wan Yussof^1*, Jamaliah Jahim²

¹Faculty of Chemical and Natural Resources Engineering, Universiti Malaysia Pahang, Lebuhraya Tun Razak, 26300, Gambang, Kuantan, Pahang, Malaysia

²Department of Chemical and Process Engineering, Faculty of Engineering and Built Environment, Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor, Malaysia

Abstract

Enzymatic hydrolysis has become outstanding technology in converting lignocellulosic biomass to its xylose monomer for xylooligosaccharides (XOS) production. The present work involves an investigation on the effects of enzyme loading, agitation speed, substrate loading, temperature and hydrolysis time on enzymatic hydrolysis for XOS production. Pretreated oil palm frond bagasse by dilute nitric acid was used for enzymatic hydrolysis using Cellic HTec2. The effects of factors were analyzed by half fractional factorial design 2^5-1 using Design Expert with Response Surface Methodology (RSM) to achieve maximum XOS production. The results revealed that the best enzymatic hydrolysis condition yielded 4.13 mg/L of XOS when conducted at 5% (w/v) of substrate loading, 50 U/mL enzyme loading with 200 rpm agitation speed and 55°C for 4 hours of hydrolysis time.  Two factors that contributed to the highest production of XOS were substrate loading and enzyme loading. The model obtained in this present research is significant with p-value < 0.0001 and R-squared of 0.9545. It is recommended that model had a maximum point which is possible for the optimization process later. Overall, the findings of this study suggest that Cellic HTec2 is a suitable candidate for enzymatic hydrolysis of pretreated OPFB for higher XOS production.

Keywords: Oil palm frond bagasse, Enzymatic hydrolysis, Cellic HTec2, Xylooligosaccharides, Response surface methodology

Muhammad Farooq¹, Shujait Ali¹, Muhammad Zubair^2*, Qudrat Ullah¹, Huma Jamil¹,  Muhammad Haroon¹, Abdul Ghaffar¹

¹Department of Theriogenology, University of Agriculture, Faisalabad, Pakistan

²Faculty of Veterinary and Animal Sciences, University of Poonch, Rawalakot, AJK, Pakistan

Abstract

Teddy is highly proliferative goat breed, as female of this breed are famous for high twining rates. Feed supplementation of olive oil has been shown to improve semen quality of goat bucks.  In this study, the effect of feed supplementation with olive oil on serum testosterone, triiodothyronine (T3), thyroxine (T4) and some biochemical metabolites in teddy goat bucks were investigated. For this purpose, 9 adult male goats, with clinically normal reproductive tract, were randomly separated into by three equal assemblies A, B and C. Animals in Cluster A were fed control ration (control group), whereas goats in group B and C were nourished with complemented 15 and 30 ml Olive oil, respectively, in morning daily for 8 weeks. Blood was collected weekly from each experimental animal and analyzed for serum testosterone, T3 and T4 concentration through ELISA. Similarly, serum alanine aminotransferase (ALT), Aspartate aminotransferase (AST), total cholesterol, triglycerides and glucose were determined using commercially available kits. Results revealed that serum concentrations of testosterone, T3 and T4 were higher (P<0.05) in bucks of groups B and C compared to those of control group. However, differences in concentration of these hormones between bucks of the former two groups were non-significant. Among biochemical metabolites, serum ALT, total cholesterol and triglycerides differed significantly (P<0.05) among three groups, with highest in control group and lowest in group C. Serum AST activity was also lower in bucks of assembly B and C than control, but, changes between groups B and C were non-significant. Similarly, the treatment had no effect on serum glucose concentrations. Based on results of the present studies, it was concluded that feed supplementation of olive oil improves semen quality and libido of Teddy goat bucks. However, its effects on health biomarkers and fertility rates of buck may be investigated before making any recommendation.                                   

Keywords: Olive oil, Thyroxin, Tri-iodothyronine, Albumin, Globulin, Triglycerides

Lani Mohd Nizam¹, Adnan Nur Ardawati¹, Mohd Maidin Nurmahani^1*, Ibrahim Roshita², Hassan Zaiton³

¹School of Food Science and Technology, Universiti Malaysia Terengganu, 21030 Kuala Nerus, Terengganu, Malaysia

²Department of Chemical Engineering Technology, Faculty of Engineering Technology, Universiti Malaysia Perlis, Uniciti Alam Campus Sg. Chuchuh, 02100 Pedang Besar, Perlis, Malaysia

³Faculty of Science and Technology, Universiti Sains Islam Malaysia (USIM), Bandar Baru Nilai, 71800 Nilai, Negeri Sembilan, Malaysia

Abstract

Kerabu Mangga is a fruit salad that is made from unripe matured mangoes. This salad is prepared fresh mixed with other ingredients. Since this salad has limited shelf life, the mango were dried at 60^oC for one and two hours, then mixed with other ingredients in an attempt to make this salad has longer shelf life and readily available when mangoes are not in season. The effects of drying on water activity (a_w), microbial load, shelf life of ‘Kerabu Mangga’ during storage at room (28 ± 2ºC) and chilled (5 ± 1ºC) temperatures as well as determination acceptance and nutrient compositions of the prepared ‘Kerabu Mangga’ were carried out. Drying treatment reduced the initial water activity (a_w) of fresh mango from 0.994 to 0.953 and 0.874 after 1 and 2 h drying, respectively, and the microbial load was reduced (~ 0.6 log₁₀ CFU/g) after drying treatments. Drying at 60°C affected significantly (p<0.05) the appearance and colour of the dried mango slices, without affecting the overall acceptability of the prepared Kerabu Mangga.  Storage temperature affected significantly (p<0.05) the microbial load (Total Plate Count), where chiller storage took 10 days  compared to 12 h for room temperature to reach spoilage to occur (normally at log₁₀ 6.00 CFU/g). For the nutrient compositions, only carbohydrate contents showed significant increased at (P<0.05), however, vitamin C content showed significant decreased (P<0.05). Drying for only 1 and 2 hours was found to be suitable for partially dried ‘Kerabu Mangga’ which resulted in negligible effect on its overall acceptance. Drying the mango slices at 60^oC for 2 h resulted in longer shelf life than 1 h or without heat treatment.

Keywords: Microbiological quality, Sensory evaluation, Dried mango, Kerabu mangga

Muhamad Asri Hashim¹, Faridah Yahya^1*, Wan Aida Wan Mustapha²

¹School of Food Science and Technology, Universiti Malaysia Terengganu (UMT), Kuala Nerus, Terengganu, Malaysia

²School of Chemical Sciences and Food Technology, Faculty of Science and Technology, Universiti Kebangsaan Malaysia (UKM), Bangi, Selangor, Malaysia

Abstract

Lemongrass is a well-known aromatic herb due to its strong lemony odour which contributes to several volatile compounds such as citral, β–myrcene and limonene. Volatile compounds of the aromatic herb are consequently difficult to restrain due to high volatility and adverse effect caused by thermal treatment applied during processing. Therefore, this study was conducted to determine the effect of different drying methods on the morphological structure, colour profile and citral concentration of lemongrass powder. Lemongrass powder was prepared by drying the fresh lemongrass stalks with oven drying, vacuum drying and freeze-drying. The yield of lemongrass powder resulted after drying processes were in the range of 9.92-11.09%. The morphology structures of all lemongrass powders were flake-like structure, irregular size, shrunk and appeared of pores. The freeze-dried powder was brighter in colour with L* value of 84.51 ± 1.64 and obtained the highest citral concentration of 321.41 ± 19.97 ppm. This study suggested that freeze-drying was the suitable method for preserving the colour qualities and citral compound of lemongrass powder. The freeze-dried powder of lemongrass has high potential to be applied in the food and beverage products.

Keywords: Lemongrass, Freeze dried powder, Drying methods, Colour profile, Citral concentration

Aidilla Mubarak^1*, Zakirah Safi Othman¹, Nurul Ulfah Karim²

¹School of Food Science and Technology, Universiti Malaysia Terengganu, 21030 Kuala Nerus, Terengganu, Malaysia

²School School of Fisheries and Aquaculture Science, Universiti Malaysia Terengganu, 21030 Kuala Nerus, Terengganu, Malaysia

Abstract

Clove (Syzgium aromaticum L.) essential oil has been reported for its potent antioxidant and antimicrobial activities. In this study, clove essential oil was incorporated with gelatin-chitosan solution to develop an edible film (CEO film) for fish preservation. The objective was to determine the effectiveness of this edible film in controlling physical, biochemical and microbial changes in fillet of silver pomfret (Pampus argenteus). The effectiveness of this film was compared with uncoated fillet (control), and gelatin-chitosan film (GC film). The formulated film was tested for water solubility and antimicrobial activity against four selected microorganisms: Escherichia coli, Pseudomonas aeroginosa, Salmonella enterica and Bacillus cereus. The effectiveness of the formulated film on the silver pomfret fillet was evaluated based on weight loss, pH, firmness, total volatile basic nitrogen (TVB-N) and total plate count (TPC) of the fish fillet. The CEO films intermediately inhibit the growth of E. coli and S. enterica. Meanwhile, GC film did not show inhibition on the growth of tested microorganisms. CEO film had lower water solubility compared to GC film. CEO film was observed to reduce weight loss (p<0.05), lower pH on day 6 (p<0.05), and increase firmness of fish fillet when compared to the control (p<0.05). Fish fillet applied with CEO film also had lower TVB-N value and microbial count. This study shows that the CEO film has antimicrobial properties which can benefit fish preservation. Improvement for developing the edible film with acceptable properties is thus important to extend the shelf life of fish fillet.

Keywords: Clove, Essential oil, Edible film, Fish fillet, Shelf life

Haslinda Wan Hamat^1,2, Mohd Nizam Lani^2*, Yusnita Hamzah², Rozila Alias³, Zaiton Hassan⁴

¹Food Safety and Quality Laboratory, Terengganu Health State Department, Kg. Bukit Tunggal, Terengganu, Malaysia

²School of Food Science and Technology, Universiti Malaysia Terengganu (UMT), Terengganu, Malaysia

³International Halal Institute Universiti Selangor, Seksyen 7, 40000 Shah Alam, Selangor, Malaysia

⁴Faculty of Science and Technology, Universiti Sains Islam Malaysia (USIM), Negeri Sembilan, Malaysia

Abstract

Keropok lekor is a popular Terengganu heritage traditional snack and its microbiological safety is one of the important aspects should be of concern. Thus, the present study was carried out to assess microbiological status of keropok lekor, and its production premises in Kuala Terengganu and Marang. A total of 136 samples were collected randomly from eight premises (in three replicates) comprising of raw materials, food contact surfaces and ready to eat (RTE). All samples were analysed for aerobic plate count (APC), total coliforms (TC) count, Escherichia coli and detection of foodborne pathogens. Results showed that the APC and TC count in raw materials (fish flesh, sago starch, ice, dough and chilli paste) ranged from below the detection limit (< 1.0 log₁₀ CFU/g) to 6.7 log₁₀ CFU/g and 4.6 log₁₀ CFU/g, respectively. While, food contact surfaces have the APC and TC in the range of < 1.0 to 6.4 log₁₀ CFU/cm² and < 1.0 to 4.1 log₁₀ CFU/cm², respectively. The food handlers hand swabs had APC and TC counts between 2.2 to 6.4 log₁₀ CFU/cm² and < 1.0 to 4.4 log₁₀ CFU/cm², respectively. RTE keropok lekor and dipping sauce contained APC in 1.8 to 5.5 log₁₀ CFU/g and < 1.0 to 5.1 log₁₀ CFU/g range, respectively. TC was detected as unsatisfactory level (> 1.7 lo    g₁₀ CFU/g) in three keropok lekor samples. E. coli was found in 10.29% of samples and all of them were non-diarrheagenic serotypes. Two RTE keropok lekor and display containers were contaminated with E. coli. Coagulase positive staphylococci, Salmonella and Vibrio parahaemolyticus were detected in four, two and one samples, respectively, with none of them found to have Vibrio cholerae and Listeria monocytogenes. High prevalence of indicator organisms in food contact surfaces and food handlers hand indicated that hygiene practices were not well implemented. The unsatisfactory levels of presence of APC, TC and E. coli in RTE keropok lekor also described cross contamination due to inadequate hygiene practices after cooking process.

Keywords: Cross contamination, Food contact surfaces, Food handlers, Hygiene, Indicator organisms

Muhammad Ahmad Zeshan¹*, Yasir Iftikhar¹, Safdar Ali², Maryam Yousaf¹, Nadeem Ahmed³,  Muhammad Usman Ghani⁴

¹Department of Plant Pathology, College of Agriculture, University of Sargodha, Sargodha, Pakistan

²Department of Plant Pathology, University of Agriculture, Faisalabad, Pakistan

³Department of Plant Pathology, Muhammad Nawaz Sharif University of Agriculture, Multan, Pakistan

⁴Institute of Soil and Environmental Sciences, University of Agriculture, Faisalabad, Pakistan

Abstract

Okra plants infected with okra yellow vein mosaic virus (OYVMV) were observed in the field for assessment of disease incidence and disease severity. Virus confirmation was done by whitefly inoculation, chip and leaf patch grafting. Electrolyte leakage and membrane stability index was calculated by recommended methods. The disease was managed by applying the mixture of buprofezin (0.001%), neem extract (0.005%) and citric acid (0.0003%). Parbhani kranti variety was most infected while Green wonder was less infected. More electrolytes leakage was recorded in infected plants while minimum in healthy plants. Neem extract was the more significant in reducing disease incidence by deterring the whiteflies from the okra crop. Citric also gave good results by repairing the plants cell damage and boosting the defense mechanism.

Keywords: Electrolyte, Geminivirus, Management, Okra, OYVMV, SAR, Whitefly

Ariffah Abdul Halim, Zamzahaila Mohd Zain, Aidilla Mubarak, Fauziah Tufail Ahmad^*

School of Food Science and Technology, Universiti Malaysia Terengganu (UMT), 21030 Kuala Nerus, Terengganu, Malaysia

Abstract

The effect of different drying treatments of stevia leaves on antioxidant activity, ferric reducing power (FRAP), total phenolic content as well as stevioside and rebaudioside A content were evaluated. Drying treatments that were applied were oven drying (80°C and 60°C), sun drying, microwave drying and freeze drying. Results of all samples were compared with fresh leaves. Antioxidant activity of dried leaves was evaluated using DPPH radical scavenging activity and ferric reducing power (FRAP) by spectrophotometer. Stevioside and rebaudioside A content were evaluated using HPLC. Among all drying treatments, microwave was found to be the highest in scavenging the DPPH radical activity with no significant different with freeze dried and fresh leaves (P> 0.05). Inhibitory concentration at 50% of microwaved leaves was the lowest compared to other dried leaves. In addition to that, microwave dried leaves exhibit highest total phenolic content at 53.95 ± 2.83 mg/g gallic acid equivalent. As for stevioside and Rebaudioside A, no degradation happened in comparison with fresh leaves after drying treatment. Stevioside appeared to be higher in content than rebaudioside A. This indicate that microwave can be good drying method, without altering the stevioside and rebaudioside A content inside the leaves, thus maintaining the sweetening properties of the leaves.

Keywords: Stevia, Drying methods, Antioxidant properties, Stevioside, Rebaudioside 

Kua Min Ping¹, Murni Islamiah², Norhayati Hadi^1,3, Hayati Mohd Yusof^{1, 2*}

¹School of Food Science and Technology, Universiti Malaysia Terengganu, 21030 Kuala Nerus, Terengganu, Malaysia

²Institute Marine Biotechnology, Universiti Malaysia Terengganu, 21030 Kuala Nerus, Terengganu, Malaysia

³School of Nutrition and Dietetic, Faculty of Health Sciences, Universiti Sultan Zainal Abidin (UniSZA), Hafsah Block, Gong Badak Campus, 21030 Kuala Nerus, Terengganu, Malaysia

Abstract

Breast cancer is a leading cause of death of women in Malaysia, accounting for 17.7% of all cancer cases reported and 31.1% of all female cases. Chemotherapy drugs are effective in breast cancer treatment but may cause physiological and psychological distress to the patient. Therefore, an alternative way to provide better anticancer treatment with less side effects is important. Honey and black seed have been reported to show strong anticancer and antioxidant properties. Thus, in the present study, methanolic extracted honey and black seed mixture (ME), aqueous extracted honey and black seed mixture (AE) and mixture of methanolic extracted honey and aqueous extracted black seed (ME+AE) were evaluated for their anticancer and antioxidant properties. Antioxidant properties of the mixtures were determined using 2,2-diphenyl-1-picrylhdrazyl (DPPH) free radical scavenging assay and the half maximal effective concentration (EC₅₀) were determined. Meanwhile, anticancer properties of the mixtures were evaluated on MCF-7 breast cancer cell line. Results revealed, in the antioxidant assays, the EC₅₀ values of AE, ME and ME+AE mixture were 4.15 mg/mL, 2.47 mg/mL and 4.17 mg/mL, respectively. In the anticancer study, there was no significant difference (p>0.05) between extraction methods on the cytotoxicity of MCF-7 cell line. The IC50 values obtained from different extraction method range between 13.27 µg/mL to 16.45 µg/mL. The presence of bioactive compounds such as alkaloid, flavonoid, phenol, tannin and saponin in honey and black seed mixture might contribute to its high cytotoxic activity. Therefore, the use of honey and black seed mixture as a health supplement for its of anticancer and antioxidant benefits should be considered.

Keywords: MCF-7, Black seed, Honey, Anticancer, Antioxidant, Phytochemical properties 

NG Khai Shin¹, Zamzahaila Mohd Zin², Nurmahani Mohd Maidin¹, Mohd Aidil Adhha Abdullah³,  Mohamad Khairi Zainol¹*

¹School of Food Science and Technology, Universiti Malaysia Terengganu, Kuala Nerus, Terengganu, Malaysia

²Centre for Fundamental and Liberal Education, Universiti Malaysia Terengganu, Kuala Nerus, Terengganu, Malaysia

³School of Fundamental Science, Universiti Malaysia Terengganu, Kuala Nerus, Terengganu, Malaysia

Abstract

This study was carried out to determine the effect of oven drying temperatures on antioxidant properties of Napier grass. Fresh samples of Napier grass were oven dried at 50, 60, 70, 80 and 90 °C for 7 h. Fresh and dried samples were extracted with water (95 °C, 30 min) and the extracts were analysed for total phenolic content (TPC) assay, total flavonoid content (TFC) assay, diphenyl-picryl-hydrazyl (DPPH) assay, Ferric reducing antioxidant potential (FRAP) assay, ferric thiocyanate (FTC) method and thiobarbituric acid (TBA) method. The data show significant changes in TPC and TFC of Napier grass. DPPH radical scavenging activity of all the samples were significantly increased after drying. Ferric reducing potential of fresh Napier grass extract (71.31 ± 1.30) and samples dried at 50 °C (66.62 ± 2.77) and 90 °C (65.58 ± 5.98) were not significant. Sample dried at 50 °C showed no significant difference with that of fresh Napier grass extract in FTC and TBA assay indicating it is a recommended drying temperature in preserving antioxidants. The results suggested that Napier grass extract possess high antioxidant properties and it can be potent natural antioxidants. It also shows that sample dried at 50 °C have the greatest antioxidant properties.

Keywords: Antioxidant activity, Oven drying, Pennisetum purpureum