This study investigated the effect of annealing treatment (at 50°C for 72 h) on hydrolysis of tapioca and sweet potato starches using a raw starch hydrolyzing enzyme namely STARGEN 001 (a blend from fungal α-amylase and glucoamylase) at sub-gelatinization temperature (35°C) for 24 h. The degree of hydrolysis of the starches was evaluated based on the dextrose equivalent (DE) value. The hydrolyzed starches were then characterized in terms of its morphology, swelling power and solubility, gelatinization and pasting properties, amylose content and x-ray diffraction pattern. After 24 h of hydrolysis, annealed starches were hydrolyzed to a greater degree with higher DE value compared to native starches (40% vs 33% for tapioca; and 29% vs 24% for sweet potato starch). Scanning electron microscopy (SEM) micrographs revealed a more porous granules and rougher surface in annealed starches than their native counterparts. The swelling power and solubility of annealed starches decreased significantly. Annealing was found to affect the pasting properties of the starches appreciably and increase the starch gelatinization temperature. The amylose content in hydrolyzed annealed tapioca and sweet potato starches increased while no significant changes observed in the X-ray diffraction of those starches. This study shows that the annealing treatment can be used as a way to increase the degree of hydrolysis of tapioca and sweet potato starches at sub-gelatinization temperature using a raw starch hydrolyzing enzyme.
Starch blend films made from sago and mung bean were prepared by casting with glycerol as the plasticizer and subsequently exposed to ultraviolet (UV) irradiation for 2 h. The films were characterized by thickness, moisture sorption isotherms, X-ray diffraction and Fourier transform infrared (FTIR) spectroscopy. All films produced were colorless while incorporation of glycerol resulted in more flexible and manageable films. Moisture sorption isotherms for all films showed sigmoidal shape and the control films showed slightly higher curve than treated films. While for X-ray analysis, the control and treated films for all formulations showed similar pattern, however for treated films showed more crystalline character. UV radiation showed affect on X-ray diffraction and sorption isotherms; however the UV radiation did not affect the spectra pattern of FTIR.
This research was aimed to examine the ability of breadfruit OSA starch (BOSA) to stabilize fish and microalgae oil emulsions. Fifteen percent of BOSA or pre-heated BOSA (7.5%) and maltodextrin (7.5%), or mixture of unheated BOSA (7.5%) and maltodextrin (7.5%) were used to stabilize 10% fish and microalgae oils. Characterization of native starch and BOSA included measurement of moisture, starch and amylose content, degree of substitution (DS), emulsification capacity, starch microstructure and thermal properties. The emulsion stability was monitored by emulsification index (EI), mean droplet size (D32), microstructure using photomicroscope and Peroxide Value (PV). Modification of starch (DS, 0.0243) caused decreasing in starch and amylose content to 75.34% and 27.62%, respectively. Starch thermal properties also decreased the onset temperature to 71.23°C (BOSA). Emulsions prepared with pre-heated mixture of BOSA and maltodextrin both in fish and microalgae oils have the smallest droplet size (D32 4.45 ± 0.09 µm and 3.54 ± 0.22 µm, respectively). Microalgae oil emulsions showed significantly (p
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.
Characterization and quantification of carotenoid compound is complicated, costly and timeconsuming. The accuracy and reliability of the data depend solely on the standard and to High Performance Liquid Chromatography (HPLC) analysis but the major constraint is to acquire and to maintain the pure standards. Carotenoid standards are commercially available but they are expensive and are prone to isomerization and oxidation. Thus, the purpose of this study is to establish an analytical method for isolating β-carotene by using open column chromatography (OCC) from pumpkin (Cucurbita moschata) to be used as one of the carotenoid standards for determination of total and individual carotenoid. Pumpkin with orange flesh has been chosen due to the non-seasonal nature and its availability all year-round. This study demonstrated that the purity of β-carotene standard; determined by HPLC was ranged from 92.21 to 97.95%. The standard curves with five different concentrations of β-carotene extract from pumpkins in triplicate were constructed by plotting the peak area against the concentration. The coefficient of correlation was 0.9936. Therefore, this study established that pumpkin can be a reliable source of beta-carotene standard as it is cheap and commonly available throughout the year.
In nature, environmental factors highly influence the carotenoid composition in pumpkin plants and these factors were difficult to control; thus, carotenoid content is varied quantitatively and qualitatively. However, certain parameters can be controlled and this can be conducted in the laboratory through biogenesis manipulation. This approach uses environmental stress as a tool to alter the carotenoid pathway in the plants. The main objective of this study was to observe the inhibiting and enhancing effect of abiotic stress on individual carotenoid accumulation in pumpkin plants under light and dark conditions. The abiotic stresses used were plant elicitors which consisted of Ultra Violet light exposure, Polyethylene Glycol 4000, Salicylic Acid, and half strength nutrients using Murashige and Skoog Salt. After two weeks of treatments, the pumpkin leaves and stems were harvested, freeze dried and extracted to determine the carotenoids compound using High-Performance Liquid Chromatography (HPLC). Results showed that there was a significant difference (p
Bacillus cereus is a soil inhabitant gram positive bacterium, and is known to cause severe food poisoning. The objective of this study was to isolate and identify the presence of Bacillus cereus s.l. from selected ready to eat cereals purchased randomly from local supermarkets in Kuching and Kota Samarahan, Sarawak. The result showed that four of the 30 food samples were detected to be contaminated by B. cereus s.l. . Our findings suggested that it is important for the public to be aware of the safety of RTE cereals consumption, as it is possible that B. cereus s.l. may be present in high count number and pose hazardous health effects to the consumers.
The experimental water flux of the forward osmosis (FO) process is much lower than the
theoretical flux due to the existence of the internal concentration polarisation (ICP), external
concentration polarisation (ECP), and membrane fouling. In the present work, vibration was
integrated with the FO process to enhance water flux in water and Mao (Antidesma bunius L.
Spreng) juice concentration. In addition, the capability of the FO process in preserving
phytochemicals was studied. The use of the vibration assisted technique could enhance the
water flux up to 23% during the FO process of distilled water due to the reduction of ICP, and
a much higher water flux enhancement (up to 70%) was attained during the FO of Mao juice
due to the reduction of ICP, ECP, and fouling. Phytochemicals including total phenolic
compounds, anthocyanin, and ascorbic acid were preserved up to 82.7, 72.6, and 95.9%,
respectively. These results suggest that membrane vibration is a promising technique for the
enhancement of the FO process performance.
Algal have attracted attention from biomedical scientists as they are a valuable natural
source of secondary metabolites that exhibit antioxidant activities. In this study, singlefactor
experiments were conducted to investigate the best extraction conditions (ethanol
concentration, solid-to-solvent ratio, extraction temperature and extraction time) in extracting
antioxidant compounds and capacities from four species of seaweeds (Sargassum polycystum,
Eucheuma denticulatum , Kappaphycus alvarezzi variance Buaya and Kappaphycus alvarezzi
variance Giant) from Sabah. Total phenolic content (TPC) and total flavonoid content (TFC)
assays were used to determine the phenolic and flavonoid concentrations, respectively, while
2,2-azinobis-3-ethylbenzothiazoline-6-sulfonic acid (ABTS) and 2,2-diphenyl-1-picylhydrazyl
(DPPH) radical scavenging capacity assays were used to evaluate the antioxidant capacities of
all seaweed extracts. Results showed that extraction parameters had significant effect (p < 0.05)
on the antioxidant compounds and antioxidant capacities of seaweed. Sargassum polycystum
portrayed the most antioxidant compounds (37.41 ± 0.01 mg GAE/g DW and 4.54 ± 0.02 mg
CE/g DW) and capacities (2.00 ± 0.01 μmol TEAC/g DW and 0.84 ± 0.01 μmol TEAC/g DW)
amongst four species of seaweed.
Use of raw seaweed for direct consumption and its extract in food production has increased
steadily throughout the world. However the ability of metal sorption in seaweed may result in
accumulation of some heavy metals which could be harmful to consumers. Tissue culture has
been considered as an alternative method to produce uncontaminated seaweeds as seedlings
for sustainable farming and raw materials for various industries including food production. In
this study, Inductively Coupled Plasma Optical Emission Spectroscopy (ICP-OES) was used
to determine the metal concentration in both field cultured and tissue cultured Kappaphycus
alvarezii and Gracilaria changii. Results indicated that concentration of heavy metals with great
scientific importance such as arsenic (As), cadmium (Cd) and lead (Pb) from tissue cultured
samples has met the specific standard of health requirement from Joint FAO/WHO Expert
Committee on Food Additive (JECFA) and Health Council and National Medicine Academy of
France. Tissue cultured seaweeds also appeared to have lower As, Cd and Pb concentrations
as compared to field cultured seaweeds. This may due to the stable and clean environment
provided in tissue culture, contrasting with uncontrollable seasonal inflow of heavy metals in
the field.
Vibrio cholerae still represents a significant threat to human health worldwide despite the advances in hygiene, consumer knowledge, food treatment and food processing. In Malaysia, statistics in year 2009 have shown that among the food and water borne diseases, food poisoning has the highest incidence rate of 36.17 per 100,000 populations and with a mortality rate of 0.01 per 100,000 populations. In this study, 22 seafood samples comprising of fish, squid, crustacean and mollusks purchased from wet market and supermarket were analyzed. The Most Probable Number (MPN) and real time PCR was used to enumerate the Vibrio cholerae in seafood sample. The results showed that MPN-real time PCR of the samples from wet market had a maximum of >1100 MPN/g compare to 93 MPN/g enumerated from the MPN plate. The MPN-real time PCR in the samples from supermarket indicated 290 MPN/g as compared to 240 MPN/g enumerated from the MPN plate. The standard curves showed that there was a good linear correlation between the Ct values. The minimum level of detection of Vibrio cholerae standard DNA at targeted gene was 3 x 10-5 ng/μl.
Caenorhabditis elegans (C. elegans) have been widely used as an infection model for mammalian related pathogens with promising results. The bacterial factors required for virulence in non-mammalian host C. elegans play a role in mammalian systems. Previous reported that Salmonella found in vegetable and poultry meat could be potential health hazards to human. This study evaluated the pathogenicity of various serovars of Salmonella enterica (S. enterica) that recovered from local indigenous vegetables and poultry meat using C. elegans as a simple host model. Almost all S. enterica isolates were capable of colonizing the intestine of C. elegans, causing a significant reduction in the survival of nematodes. The colonization of Salmonella in C. elegans revealed that the ability of S. enterica in killing C. elegans correlates with its accumulation in the intestine to achieve full pathogenicity. Using this model, the virulence mechanisms of opportunistic pathogenic S. enterica were found to be not only relevant for the interactions of the bacteria with C. elegans but also with mammalian hosts including humans. Hence, C. elegans model could provide valuable insight into preliminary factors from the host that contributes to the environmental bacterial pathogenesis scenario.
Classification of whole grain rice using only amylose content is not practical to predict starch
viscosity for end product recommendation. This study aims to characterize and categorize
whole-grain rice based on pasting profile of Rapid Visco Analyzer (RVA). The rice cultivars
showed a wide range of peak viscosity (89.98 to 280.95 RVU), hold viscosity (59.97 to 211.56
RVU), breakdown viscosity (-0.33 to 130.67 RVU), final viscosity (111.25 to 390.75 RVU),
setback viscosity (-44.47 to 205.67 RVU) and pasting temperature (74.17 – 91.15o
C). Stability ratio and final viscosity explained 68.8% of total variance in the RVA profiles. The rice cultivars
could be grouped into high (>0.95), medium (0.65-0.95) and low (< 0.65) stability ratio,
followed by high (>300 RVU), medium (140 – 250 RVU) and low (< 140 RVU) final viscosity.
The classification could serve as a basis for effective rice selection according to functional
properties of whole grain rice.
Goat milk is a highly nutritious and an ideal wholesome food. Today, an increase in demand by
consumers is witnessed towards consuming goat milk, mainly owed to their rich nutraceutical
value. In this study, novel goat milk bar was developed by incorporating rose flower extracts
as an added ingredient (concentration level: 0, 5, 10, 15 and 20%), and by using two different
types of natural sweeteners (cane sugar and palm sugar). The nutrition bars were evaluated
for proximate composition, texture properties and sensory qualities. Results obtained were
encouraging and the new goat milk based nutritional bar formulation with added rose extracts
certainly paves way for future commercial exploitation of the product. Goat milk, owing to its
rich nutraceutical value, and rose extracts owing to the dual functions of a natural antioxidant
and antimicrobial agent, can be beneficial for extending the shelf life of this novel product
under room or refrigerated temperatures, thus attracting better markets.
The present work aimed to determine the antagonistic effect of probiotic-fermented soy against oral pathogens. Indigenous oral probiotics (Streptococcus salivarius Taylor’s Univer- sity Collection Centre (TUCC) 1251, S. salivarius TUCC 1253, S. salivarius TUCC 1254, S. salivarius TUCC 1255, and S. orisratti TUCC 1253) were incorporated into soy fermentation at 37°C for 24 h. Growth characteristics, β-glucosidase activity, and total isoflavones content of Streptococcus strains following soy fermentation were analysed. Antimicrobial test of Streptococcus-fermented soy was carried out against oral pathogens Enterococcus faecalis American Type Culture Collection (ATCC) 700802, Streptococcus pyogenes ATCC 19615, and Staphylococcus aureus ATCC 25923. Streptococcus strains showed a significant increase in growth following soy fermentation. S. salivarius TUCC 1253-fermented soy showed signif- icantly higher extracellular β-glucosidase activity and amount of aglycones. S. salivarius TUCC 1253-fermented soy showed antimicrobial effect against all oral tested pathogens in both aerobic and anaerobic conditions. These results showed that S. salivarius TUCC 1253-fermented soy could potentially be used as a preventive action or alternative treatment for oral infections.
Available studies to determine the total phenolic content and antioxidant capacities of cooking
pastes available in Malaysia were currently limited. This study aimed to evaluate the total
phenolic content (TPC) and antioxidant capacity of seven types of mix spices cooking paste
in raw and cooked condition (N=33). Samples were selected based on market availability.
TPC was determined by Folin-Ciocalteu method and the antioxidant capacities were evaluated
by DPPH free radical scavenging assay, ferric reducing antioxidant power (FRAP) assay and
ABTS free radical scavenging assay. Results were presented in dry weight (DW). TPC in the
paste samples ranged from 246.25 to 370.57 mg GAE/100 g whereas antioxidant capacities
ranged from 728.54 to 1267.66 μmol TE/100 g for DPPH assay, 1247.15 to 1886.89 μmol
TE/100 g for FRAP assay and 833.19 to 1589.40 μmol TE/100 g for ABTS assay. Chicken, fish
and vegetarian curries were top three samples with the highest TPC and antioxidant capacities
values. Cooking process had caused increment in TPC and antioxidant capacities of all paste
samples, with Rendang paste showed the greatest increase in TPC (21.48%) and antioxidant
capacities (24.26%-49.66%) after cooking. Linear relationships were observed between TPC
and DPPH antioxidant capacity (r=0.545), FRAP antioxidant capacity (r=0.840) and ABTS
antioxidant capacity (r=0.623). A positive relationship between TPC and antioxidant capacities
indicated that polyphenol is one of the sources of antioxidants in mix spices cooking paste.
Further investigations on the active compounds in the cooking pastes are needed to determine
the bioavailability and effect of these compounds in human
Ultraviolet (UV) light especially UV-C has been used to sterilize fruits and vegetables. However, overdose of UV-C irradiation could cause brownish-red colouration to products such as banana fruit. Therefore, the objectives of this study were to: (1) examine the effect of UV-C irradiation at different doses on the surface colour of Berangan banana fruit during ripening; (2) determine polyphenol oxidase (PPO) activity after irradiated with different doses of UV-C, and (3) examine the effectiveness of three browning assessment methods (subjective score, browning index derived from Lab colour space and optical density of 420 nm) in response to PPO activity of UV-C irradiated Berangan banana fruit. Mature green Berangan banana fruit were irradiated with 0, 0.01, 0.02, 0.03 and 0.04 kJ/m2 UV-C. After irradiation, the fruit were initiated to ripening using 1 mL/L ethylene for 24 h. Then, the fruit were allowed to ripen in 27oC and fruit of day 0, 1, 3 and 5 were sampled for peel colour (L*, a*, b*, C* and ho), browning assessment (three methods) and PPO assay. The peel colour, browning assessment using subjective score and optical density, and PPO activity of Berangan banana fruit were affected significantly (P ≤ 0.05) by interaction of radiation dose x ripening day. The values of L*, b*, C* and ho decrease while a* values increase as fruit irradiated with 0.03 and 0.04 kJ/m2 UV-C indicating brownish-red has occurred. Fruit irradiated with 0.04 kJ/m2 UV-C discoloured by ripening day 3 while those irradiated with 0.03 kJ/m2 discolored by day 5. Similar result was obtained when fruit assessed for its browning using subjective score and optical density. A contrary result was obtained in PPO activity where UV-C irradiation has inhibited Berangan banana fruit PPO activity by ripening day 5. Correlation analysis showed that browning index that derived from colour space is highly related to PPO activity with coefficients of 0.93. As conclusion, the lethal dose causing browning for Berangan banana fruit is 0.03 kJ/m2 and browning index that derived from colour space is most effective to correlate browning with PPO activity.
The application of Light Emitting Diodes (LEDs) in agricultural sector has become popular in recent years. LEDs can even be used in total absence of natural sunlight in raising indoor vegetables and ornamental plants. Appropriate light spectral regions must be studied according to crop species or varieties, especially for plants with high commercial values. The present experiment was conducted to determine the effects of monochromic LED of Red (R) and Blue (B), and their combinations at 1:1, 1:2 and 2:1,at 18 W and 240 V, on production of Lactuca sativa cv. Fire Red in controlled laboratory environment in total absence of natural light. Each LED irradiation treatment was assigned as sub plot with photoperiods (PPs) ranging from 12 h to 18 has main plots in a split plot design to study their combined effects on growth, pigment and ascorbic acid (AA) contents of this attractive red colour vegetable. Seedlings in moist jiffy blocks at one week after sowing were transferred to polyvinyl chloride (PVC) troughs of 5 cm diameter containing quarter strength Hoagland solution at electrical conductivity ranging from 1,100 to 1,300 μS/cm and pH 6-7. Plants were grown with nutrient film technique at a distance of approximately 8 cm below LED. Results obtained showed that R was not appropriate for growing this vegetable while analysis of variance indicated that plants irradiated with B gained the greatest plant height at five weeks at harvest, but these plants had the lowest number of leaves. Highest fresh weight (FW) as marketing attribute of this vegetable was obtained with 18 h PP. When combined 18 h PP with BR or 2BR, it was the best for production of L. sativa cv. Fire Red with the highest anthocyanin content.
The aim of this study was to produce a high-protein, wet yellow noodle by the incorporation of surimi powder as a protein source and evaluate the effects of the physicochemical and sensory properties of the
noodle. The surimi powder was prepared by oven drying the wet surimi at 60oC until the moisture content was below 10%. Five concentration levels of surimi powder substitutions were used (0, 5, 10, 15 and 20%), and as a result, the noodles showed a trend that significantly increased (P
The study was conducted to investigate fatty acid composition, rheological properties and crystal formation of rambutan fat and cocoa butter. The results showed that lauric acid, palmitic acid, and stearic fatty acid in rambutan fat were less than cocoa butter, but oleic acid found almost the same. The crystal formation of cocoa butter was not complex at 25oC, while rambutan fat and their mixture shown complicated network of crystal form. The Newton, Bingham and Casson plastic rheological models was used to describe fat flow in this experiment and the result showed that rambutan fat had higher viscosity than cocoa fat. Based on the results the study recommended that mixture proportion up to 30% rambutan seed fat can be used as a cocoa butter substitute whereas higher proportion completely alters original cocoa butter properties. Therefore, there is feasibility of using the rambutan fat to substitute cocoa butter and the mixtures of the two fats in suitable proportion in chocolate manufacturing.