Nor Hayati Ibrahim^*, Tengku Nur Dayana Tengku Zakaria, Yusnita Hamzah

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

Abstract

This study was conducted to investigate the influence of extraction conditions i.e. water:fronds ratio (0.5:1 – 12:1), temperature (25 – 90˚C) and pH (3 – 11) on extraction yield, crude protein content and emulsifying capacity of mucilage from Talinum paniculatum fronds. Response surface methodology with a face cantered-central composite design was applied to optimize the extraction conditions. With 20 experimental runs, extraction yield, crude protein content and emulsifying capacity of the mucilage were recorded to be 2.32 – 4.90%, 15.05 – 30.97% and 8.05 – 37.93%, respectively. Response surface analyses showed that increases in mucilage yield were mainly due to significant (p < 0.05) quadratic effect of pH and also synergistic effect between water:fronds ratio and pH. In contrast, significant (p < 0.05) quadratic effect of temperature and its synergistic effect with water:fronds ratio led to increase in emulsifying capacity of the mucilage. Furthermore, linear effect of pH seemed to significantly (p < 0.05) increase the crude protein content, in addition to significant (p < 0.05) synergistic effect between water:fronds ratio and pH. Experimental data for each response were best fitted with a quadratic model, having high coefficients of determination (R² = 0.81 – 0.98) and no lack-of-fit. The optimum conditions for mucilage extraction from T. paniculatum were obtained at water:fronds ratio of 8.4:1, temperature of 90 ⁰C and pH of 8, providing 3.44 % yield, 29.35 % crude protein content and 34.00 % emulsifying capacity of T. paniculatum mucilage.

Keywords: Mucilage, Talinum paniculatum, Extraction conditions, Optimization, Emulsifying capacity

Amiza Mat Amin, Zaliha Harun*, Intan Liyana Muhamad Roslan

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

Abstract

In this study, optimization of enzymatic protein hydrolysis conditions of flower crab meat (FCM) to yield maximum angiotensin converting enzyme (ACE) inhibitory activity was carried out. First, screening of commercial food grade enzymes (Alcalase®, Neutrase®, Protamex® and papain) was carried out to select the most suitable proteinase to yield ACE inhibitory activity. A 3-level face-centered central composite design (CCD) was employed to optimize four hydrolysis conditions including temperature (45-55°C), hydrolysis time (1-3 hr), pH (6-8) and enzyme to substrate ratio (E/S) (1-3%). Half maximal inhibitory concentration (IC₅₀) of FCM hydrolysate prepared at optimum condition was also determined. It was found that the highest ACE inhibitory activity (85.52%) was given by Neutrase® after 2 hr hydrolysis. Hence, Neutrase® was used in the optimization study. It was found that the enzymatic hydrolysis condition of FCM towards ACE inhibitory activity could be predicted by a quadratic model. The optimum enzymatic hydrolysis condition to obtain maximum ACE inhibitory activity was at temperature of 54°C, E/S of 3%, pH of 7 and hydrolysis time of 1 hr. It was found that the predicted value of ACE inhibitory activity (97.21%) was close to that of experimental value (90.34%) with the IC₅₀ of 0.425±0.05 mg/ml.

Keywords: Optimization, Angiotensin-I Converting Enzyme, Enzymatic hydrolysis, Flower crab

Pantipa Na Chiangmai^1*, Monnat Yamying¹, Pimjai Meetum¹, Siraprapa Brooks², Pakpoom Rienghlam¹, Bhutharit Vittayaphattananurak Raksasiri¹

¹Faculty of Animal Sciences and Agricultural Technology, Silpakorn University, Phetchaburi IT Campus, Cha-am, Phetchaburi, 76120, Thailand

²School of Science, Mae Fah Luang University, Muang district, Chiang Rai, 57100, Thailand

Abstract

The seed collected from ethnic farmers (Pa-gha-ker-yor People), at Pala U village, Hau Hin district, Prachuap Khiri Khan province, Thailand for genetic conservation and investigating feasibility for breeding and improvement. For genetic improvement, information on either some qualification or ability to assist in the breeding process is required, such as the ability to culture seed, explants or other tissues in a sterile laboratory condition. The objective of this study evaluated the effectiveness of callus induction and regeneration upland rice seeds (var. Nikor, var. Raw Bi, var. Gi Poo and var. Nah San, var. Baw Pae Soo and var. Pae Taw Gaw Bi) collected from minority farmers and some lowland cultivated rice varieties (var. RD51 and var. Pratumtani1) in Thailand. The culture medium used in the study were derived from the previously reported formulations that are highly effective in inducing callus (MS1, MS2 and MS8) and regenerating (MS1, MSa and MSb) in rice. The different formulas in medium were from various combinations of plant growth regulator both or either on cytokinin (Benzyl aminopurine; BAP) and/or auxins (Napthalene acetic acid; NAA, 2,4-dichlorophenoxy acetic acid; 2,4-D) for callus induction and regeneration. For statistical analysis, the data have been analyzed using analysis of variance (ANOVA). The means among treatments were compared with the Duncan’s new multiple range test (DMRT). The results showed the increasing on callus induction percentage were recorded on MS2 (86%) and MS8 (90.5%) mediums studied on immature and mature seed, respectively. The callus of upland rice varieties induced on a medium which showed higher percentage (90.5% callus induction on MS8 and 0% on MS1) were selected to shoot regeneration experiment contained three media (MS1, MSa, and MSb). However, in the regeneration process, there is no significant difference between medium; the percentage of regenerating callus of these media at 6.25%, and the interaction between media and varieties of rice.

Keywords: Indigenous rice genetic, Plant hormone, Micropropagation, Genetic conservation, Culture medium

Aidilla Mubarak^1*, Kevin D. Croft², Catherine B. Bondonno³, Nurul Sakinah Din¹

¹School of Food Science and Technology, Universiti Malaysia Terengganu, 21030 Kuala Nerus, Terengganu, Malaysia
²School of Biomedical Science, The University of Western Australia, M570, Level 4, Medical Research Foundation Building, Rear 50 Murray St, Perth, Western Australia 6847, Australia

³School of Medical and Health Sciences, Edith Cowan University, 270 Joondalup Drive, Joondalup, Western Australia 6027, Australia

Abstract

Information on the composition of chlorogenic acid, caffeine and antioxidant activity of Coffea liberica is scarce, albeit the importance of this species in some parts of the world. This study assessed the composition of chlorogenic acid, total phenolic, caffeine and free radical scavenging activity in green and roasted C. liberica in comparison to C. arabica. The compositions of these compounds were also investigated in C. liberica at different roasting degree. We found a comparable amount of chlorogenic acid in green C. liberica and C. arabica. However, roasted C. arabica had a significantly higher chlorogenic acid content than roasted C. liberica (p<0.05). Chlorogenic acid content significantly reduced in C. liberica after roasting when compared to green beans (p<0.05). There was an insignificant difference of caffeine content between the green and roasted beans of both coffee varieties. Total phenolic content were of comparable value between C. liberica and C. arabica for both green and roasted beans. There was a trend for higher total phenolic content in roasted C. liberica when compared to green beans, although significant difference was observed only in medium-dark roast (p<0.05). DPPH scavenging activity was comparable between C. arabica and C. liberica for both green and roasted beans, and was significantly reduced in C. liberica after roasting (p<0.05). Both green C. arabica and C. liberica had similar DPPH scavenging activity to the standards (BHT and α-tocopherol). These data can aid in promoting the production of C. liberica alongside C. arabica that has been regarded as a premium quality coffee.                       

Keywords: Antioxidant, Chlorogenic acid, Coffea arabica, Coffea liberica, Polyphenols 

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