Bananas were chilled at 6oC and the appearance of brown spots when exposed to ambient air, a
phenomenon known as chilling injury (CI), was detected using computer vision. The system consisted of a digital colour camera for acquiring images, an illumination set-up for uniform lighting, a computer for receiving, storing and displaying of images and software for analyzing the images. The RGB colour space values of the images were transformed into that of HSI colour space which is intuitive to human vision. Visual assessment of CI by means of a browning scale was used as a reference and correlation between this reference values and hue was investigated. Results of the computer vision study successfully demonstrate the potential of the system in substituting visual assessment in the evaluation of CI in bananas. The results indicate significant influence, at α=0.05, of treatment days and temperature on hue. A strong correlation was also found between hue and visual assessment with R>0.85.
Chicken fat is a potential bioresource that can be developed into a commercial product. In this study, chicken fat, which is rich in unsaturated fatty acids, including oleic acid (C18:1) and linoleic acid (C18:2), was enzymatically interesterified with corn oil to produce a soft spread. Two interesterified products, sample 16 (4% enzyme, 4:1 mole ratio of chicken fat to corn oil, 50°C and 42 h of the interesterification process) and sample 17 (4% enzyme, 2:1 mole ratio of chicken fat to corn oil, 30°C and 42 h of the interesterification process), were selected based on the highest SFC at 30oC which were close to SFC values of commercial product. A morphological study showed that the final products had smaller and less dense fat particles, which explained the lower melting temperatures and solid fat content (3.2 and 3.5% for samples 16 and 17, respectively, at 20°C) compared to the commercial products (9.7, 6.8 and 7.7% for products A, B and C, respectively, at 20°C). However, both sample 16 and 17 had similar thermal properties to a vegetable-oil-based commercial product, with melting enthalpies (ΔH) of 58.45 J/g and 71.40 J/g, and were fully melted at 31.40°C and 35.41°C, respectively.
The physico-chemical properties of spray-dried pitaya peel powders kept at accelerated (45 ± 2°C) and room temperature (28 ± 2°C) for 14 weeks and 6 months, respectively were evaluated. Changes in physico-chemical properties of the peel powder were used as indicators of stability, while changes of the betacyanin pigment retention was used to calculate the shelf-life of the powder. Storage temperatures significantly (p < 0.05) affected all the studied parameters and Hunter a value had the most significant change. The pigment retention of peel powder was approximately 87% at 45°C and 89% at room temperature storage. Degradation of betacyanin pigment in the powder followed the first order reaction kinetics with the half-life (t1/2) of approximately 76 weeks at 45°C and 38 months at 28°C. The spray-dried pitaya peel powder had a solubility of 87 to 92% and low in powder hygroscopicity. The final Aw of the powder did not exceed 0.6 for both storage temperatures.
An improved laboratory technique for measurement of polonium-210(
210Po) in environmental
samples has been developed in Radiochemistry and Environmental Laboratory (RAS), Malaysian
Nuclear Agency. To further improve this technique, a study with the objectives to determine the
optimum conditions for
210Po deposition and; evaluate the accuracy and precision results for
the determination of 2 1 0 P o in environmental samples was carried-out. Polonium-210 which
is an alpha emitter obtained in acidic solution through total digestion and dissolution of samples
has been efficiently plated onto one side of the silver disc in the spontaneous plating process for
measurement of its alpha activity. The optimum conditions for deposition of 210Po were achieved
using hydrochloric acid (HCl) media at acidity of 0.5 M with the presence of 1.0 gram hydroxyl
ammonium chloride and the plating temperature at 90
oC. The plating was carried out in 80 mL
HCl solution (0.5 M) for 4 hours. The recorded recoveries obtained using 2 0 9 P o tracers in
the CRM IAEA-385 and environmental samples were 85% – 98% whereby the efficiency of the
new technique is a distinct advantage over the existing techniques. Therefore, optimization of
deposition parameters is a prime importance to achieve accuracy and precision results as well as
economy and time saving
Raw goat milk is recognized as one kind of nutritious food owed to its originality and
medicinal values. This study aimed to evaluate the physico-chemical and microbiological
qualities of locally produced raw goat milk prior any processing steps during storage. Milk
samples passed organoleptic test and C.O.B. test were mostly (88.89 %) failed in alcohol test.
AOAC Official method of oven drying method, Kjeldahl method and Soxhlet method were
performed in physico-chemical analysis where results obtained were partially in lined with
reported literature due to subjective factors of breeds, geographical areas and feeds. The locally
produced raw goat milk’s compositions are high in water content and low in fat percentage.
Initial total plate count, coliform count and proteolytic count tested were 3.44 log cfu/ml, 1.87
log cfu/ml and 1.97 log cfu/ml, respectively. Storage time showed significant effect on the
bacterial counts (p>0.05) of milk samples. Shelf-life of milk samples were kept up to 12 hours
under ambient temperature (3.95 log cfu/ml) had not exceeded the standard limit. The shelflife
of the milk samples were extended up to 16 days storage under refrigerated temperature
of 4°C. The microbiological quality of the milk samples showed a significant bacteriological
growth upon prolonged storage and high initial coliform count indicates possible poor hygienic
practices at farm level.
This study investigated the effects of different percentages of ethanol (0 - 100%), extraction times (1 - 5 h) and temperatures (25 - 60°C) on total phenolic content (TPC) and antioxidant activity (AA) of sapodilla pulp and peel. TPC was determined by Folin-Ciocalteu reagent method, while AA was evaluated using 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging assay, 2,2-azino-bis-(3-ethyl-benzothiazoline-6-sulfonic acid) (ABTS) radical scavenging assay, ferric reducing antioxidant power (FRAP) assay and β-carotene bleaching (BCB) assay. Based on the optimal extraction conditions used, sapodilla pulp extract had TPC of 3.89 mg GAE/g, 63.20% of DPPH scavenging activity, 4.30% of ABTS scavenging activity, 19.17% of BCB activity, and FRAP value of 15.24 mg TE/g; while its peel extract had TPC of 9.23 mg GAE/g, 92.95% of DPPH scavenging activity, 5.36% of ABTS scavenging activity, 8.14% of BCB activity, and 27.85 mg TE/g (FRAP value). Using the optimal extraction conditions for sapodilla pulp (40% ethanol as extraction solvent that extracted at 60°C for 4 h) and sapodilla peel (80% ethanol and 2 h extraction time at 40°C), highest antioxidants can be extracted from the pulp and peel.
The recovery of uranium from non-conventional sources has its importance in the security of nuclear fuel supply as well as producing a more value-added product to the contaminated source. In this paper, uranium is recovered both by developing a hydrothermal process as well as using the removal method. Developing hydrothermal process involves using high uranium concentrated starting material such as xenotime and thorium hydroxide waste produced from the monazite cracking process. Oxalate separation enable to produce a better uranium and thorium separation from the yttrium in xenotime as compared to the hydroxide precipitation. Also, a solvent extraction stage was included to separate the uranium from the thorium in the process using thorium hydroxide waste. The removal method involves using selective leaching for minerals with lower uranium content such as zircon. A better removal for uranium and thorium in zircon is achieved when a heat treatment process was done prior to the leaching stage. White zircon mineral was produced after this treatment and its quality meets the requirement for white ceramic opacifier and glaze.
Mechanical properties of blended polyethylene (PE) containing the antioxidant Irganox 1010 and the UV-absorber Tinuvin 326 were studied for future use as radiation capsule material for the TRIGA Mark II research reactor. High density and low density polyethylene were blended with the additives and tested for elongation at break, impact strength and gel content, before and after irradiation inside the nuclear reactor. Characterization via FTIR as well as determination of crystallization and melt transition temperatures through DSC were also conducted. It was found that the addition of the antioxidant at different amounts (from 0 to 4 phr) had various effects on the properties of the blended PE, with 0 phr being the amount at which there was the biggest increase in elongation at break and impact strength, post-irradiation.
Natural fiber is incompatible with hydrophobic polymer due to its hydrophilic nature. Therefore, surface modification of fiber is needed to impart compatibility. In this work,superheated steam (SHS)-alkali was introduced as novel surface treatment method to modify oil palm mesocarp fiber (OPMF) for fabrication of biocomposites. The OPMF was first pre-treated with SHS and subsequently treated with varying NaOH concentration (1, 2, 3, 4 and 5%) and soaking time (1, 2, 3 and 4h) at room temperature. The biocomposites were then fabricated by melt blending of 70 wt% SHS-alkali treated-OPMFs and 30 wt% poly(butylene succinate) in a Brabender internal mixer followed by hot-pressed moulding. The combination treatment resulted in fiber with rough surface as well as led to the exposure ofmicrofibers. The tensile test result showed that fiber treated at 2% NaOH solution and 3h soaking time produced biocomposite with highest improvement in tensile strength (69%) and elongation at break (36%) in comparison to that of untreated OPMF. The scanning electron micrographs of tensile fracture surfaces of biocomposite provide evident for improved adhesion between fiber and polymer after thetreatments.This work demonstrated that combination treatments of SHS and NaOH could be a promising way to modify OPMF for fabrication of biocomposite.
Oil palm is widely grown in Malaysia. There has been interest in the utilization of oil palm biomass for production of environmental friendly biofuels. The gasification of empty fruit bunches (EFB), a waste of the palm oil industry, was investigated in this study to effectively and economically convert low value and highly distribution solid biomass to a uniform gaseous mixture mainly hydrogen (H2). The effects of temperature, equivalence ratio (ER) and catalyst adding on the yields and distribution of hydrogen rich gas products were also investigated. The main gas species generated, as identified by GC, were H2, CO, CO2, CH4 and trace amounts of C2H4 and C2H6. With temperature increasing from 700 to 1000 °C, the total gas yield was enhanced greatly and reached the maximum value (~ 90 wt. % ) at 1000°C with a big portion of H2 (38.02 vol. %) and CO (36.36 vol. %). Equivalence ratio (ER) showed a significant influence on the upgrading of hydrogen production and product distribution. The optimum ER (0.25) was found to attain a higher H2 yield (27.42 vol. %) at 850°C. The effect of adding catalysts (Malaysian dolomite1, P1), Malaysian dolomite2 (GML), NaOH, NaCl, CaO, ZnO, NiO) as a primary catalyst on gas product yield was investigated, and it was found that adding dolomite showed the greatest effect with the maximum H2 yield achieved (28.18 vol.%) at 850°C.
This study attempted to investigate the effect of kiln drying on the rate of formation of ball copra. Three samples containing fifty partially dried-coconuts were placed as a single layer in three compartmentalized blocks namely, Front: Blok-1, Middle: Block-2, and Rear: Block-3 in the copra bed of the modified-Ceylon copra kiln. From each of the three blocks, thirty coconuts were selected randomly for labeling and their fresh weights were recorded. The samples were subjected to intermittent drying in the kiln by thirty five firing cycles using charcoal dust as the fuel source. The temperature distribution pattern of the three blocks during the first six firing was monitored at three hourly intervals. The weight losses of individual coconuts in each block were measured after the completion of each firing. The results showed that, there was a significant (p
This study was carried out to determine the proximate, functional and pasting properties of breadfruit starch. Breadfruit starch was isolated from matured breadfruit (Artocarpus altilis) and was analyzed for its fuctional, proximate and pasting properties. The starch contains 10.83%, 0.53%, 0.39%, 22.52%, 77.48% and 1.77% moisture, crude protein, fat, amylose, amylopectin and ash contents respectively. The average particle size, pH, bulk density and dispersibility of the breadfruit starch were 18 μm, 6.5, 0.673 g/mls, and 40.67% respectively. The swelling power of the breadfruit starch increases with increase in temperature, but there was a rapid increase in the swelling power from 70 to 80 0C. The pasting temperature of the starch paste was 84.05 0C, setback and breakdown values were 40.08 and 7.92 RVU respectively. The peak viscosity value was 121.25 RVU while final viscosity value was 153.42 RVU. This study concluded that breadfruit starch has an array of functional, pasting and proximate properties that can facilitate its use in so many areas where the properties of other starches are acceptable.
The level of total lipid and oryzanol content, an important antioxidant compound in locally produced bran was investigated. Total lipid in rice bran was extracted using 3:2 chloroform:methanol mixture yielding 16.4% fat. Oryzanol content was determined without saponification using a reverse-phase HPLC. Four fractions of oryzanol were successfully separated and quantitated. The 4 isomers were cycloartenyl ferulate, 24-methylene cycloartanyl ferulate, campestryl ferulate and mixtures of β–sitosteryl ferulate and cycloartanyl ferulate. The oryzanol content of local mixed varieties ranged from 23.7–43.0 mg g-1. The oryzanol concentration may depend on factors such as plant varieties, processing methods employed, extracting solvent used and ratio of extracting solvent to bran as well as extracting solvent temperatures. This study showed the potential of oryzanol extract from rice bran as a source of antioxidant.
A study to measure frying quality and stability of rice bran oil (RBO) compared to palm olein (PO) was conducted. The oils were used to fry French fries continuously for six hours a day up to five days at a temperature of 185 ± 5°C. Oil samples were collected and analyzed for free fatty acid (FFA), peroxide value (PV), smoke point, p-anisidine value (p-AV), iodine value (IV) and colour. At the end of the frying period for both oil samples, FFA, PV, colour and p-AV were increased whereas the IV and smoke point decreased. The rate of FFA formation of RBO was slightly lower which increased from 0.142% to 0.66% compared to PO which was from 0.079% to 0.93%. The PV of RBO showed consistent increased from 3.9 meq/kg to 13.4 meq/kg whereas PO with initial value at 3.4 meq/kg increased to 34.6 meq/kg on the fifth day. Smoke point of RBO and PO progressively dropped from 235°C to 188°C and 220°C to 178°C, respectively. The level of p-AV for RBO increased from 12.19 to 32.65 from the initial to the end of frying day whereas PO had higher rate of changes in p-AV which was from 10.45 to 60.75. The IV decreased over frying time where IV of RBO decreased from 94.5 to 66.5 while IV of PO decreased from 50.9 to 44.6. The colour of RBO showed increased in redness and yellowness but PO was darker at the end of the frying trial. In general, RBO showed better stability than the PO in deep frying of French fries.
Cantaloupes continue to ripen after harvesting which is caused by ethylene production due to climacteric behaviour during postharvest storage. In this study, the cantaloupe fruits harvested at commercial maturity were evaluated for quality attributes during three weeks of storage at 10°C and a relative humidity (RH) of 90±5%. In addition, fresh-cut samples were stored for a further 19 days at 2°C and 87% RH. The fresh-cut samples were prepared on a weekly basis by dipping into deionised water (control) at 2°C for 1 minute. The effect of postharvest storage of cantaloupe on the physico-chemical properties and microbial activity was observed prior to fresh-cut processing. It was found that firmness, luminosity (L*), and titratable acidity (TA) decreased, while total soluble solids (TSS), pH, TSS:TA ratio, microbial activity (total plate count (TPC) and yeast and mould (YM)) of the fresh-cut increased over the postharvest storage period of the fruit. Meanwhile, the orange colour and the intensity (hue angle, hab, and chromaticity) of the flesh did not differ significantly during storage. The cantaloupe stored for three weeks at a low temperature indicated a successful potential for fresh-cut processing due to good maintenance of the product quality.
The optimisation of fresh fruit bunch (FFB) sterilisation process was studied using different degree of FFB ripeness (i.e. under-ripe, ripe, overripe) and loose fruits. This study was carried out with the application of Response Surface Methodology (RSM), based on the interrelation between process temperature (X1; 100 to 120oC) and time (X2; 20 to 80 min) used for FFB sterilisation process on Free Fatty Acid, FFA (Y1,underripe FFB; Y2,ripe FFB; Y3,Overripe FFB; and Y4,loose fruits). Thirteen experimental runs were conducted per degree of ripeness using laboratory scale steriliser with varying sterilisation temperature and time, as generated by Central Composite Rotatable Design (CCRD). Raw experimental data trend showed substantial FFA increment with the increment of FFB maturity. Four polynomial models were found appropriate to predict the responses within experimental regions. Analysis regarding factor influences on each response was performed using Analysis of Variance (ANOVA) and graphical analysis. For under-ripe and ripe FFB, the temperature exerted higher and significant (p
The influence of superheated steam cooking on fat and fatty acid composition of chicken sausage were investigated at various temperatures (150, 200, and 250°C) with different time domains (2-6 min). It has been found that the fat content of raw sample was higher than that of all cooked samples. The total fat content of cooked sample, showed a linear decreasing with time at all investigated temperatures. Superheated steam produce changes in saturated fatty acid (SFA), monounsaturated fatty acid (MUFA), and polyunsaturated fatty acid (PUFA) in which their values were found to decrease in cooked samples. When different cooking conditions (temperature, time) were applied, the fatty acids were decreased as the time and temperature increased. The PUFA and MUFA were less prone to decrease at 150°C, while at this temperature there was a remarkable loss in SFA content. This cooking method considerably reduced the level of fat and SFA which have a positive effect on health. In addition it could imply a great choice for consumers to choose the healthier technique for cooking food.
The purpose of this study was to investigate the preparation of formulated water- in-soybean oil-in-water emulsions by repeated premix membrane emulsification method using a cellulose acetate membrane. The effect of selective membrane emulsification process parameters (concentration of the emulsifiers, number of passes of the emulsions through the membrane and storage temperature) on the properties and stability of the developed emulsions were also investigated. 1, 3, 6, 8-pyrenetetrasulfonic acid tetrasodium salt (PTSA) was used as a hydrophilic model ingredient for the encapsulation of bioactive substances. W/O emulsions with 7 wt% (weight percentage) PGPR displays homogeneous and very fine dispersions, with the median diameter at 0.640 μm. Meanwhile, emulsions prepared by membrane emulsification (fine W/O/W) showed the highest stability at Tween 80 concentrations of 0.5 wt.% (weight percentage). It concluded that at 7 wt.% (weight percentage) PGPR concentration and 0.5 wt.% (weight percentage) Tween 80 concentrations, the most uniform particles with minimum mean size of oil drops (9.926 μm) were obtained after four passes through the membrane. Thus, cellulose acetate membrane can be used for preparing a stable W/O/W emulsions by repeated premix ME due to low cost and relatively easy to handle.
Unprocessed ‘budu’ is a mixture of anchovies and salt that has been fermented for a period of time, and has not been heat-treated nor formulated with additional ingredients. This study analyzed Malaysian
unprocessed ‘budu’ from 12 producers for microbiological, salt, protein, histamine and 3-MCPD contents.
The results demonstrated that Malaysian unprocessed ‘budu’ were free from pathogenic Coliform, E. coli,
V. parahaemolyticus and V. cholerae contaminations. Carcinogenic 3-MCPD was below detection level of 2 ppb for all 12 samples tested. However, 58% of the unprocessed ‘budu’ had histamine content greater than the hazardous levels of 50 mg/100 g sample.
Thermal treatment is commonly applied in juice manufacturing as a method to pasteurize juices. However the heat may deteriorate some of the essential compounds in the juice, especially heat-sensitive antioxidants. Therefore non-thermal treatment such as ultraviolet (UV) ray has been proposed as an alternative for pasteurization. The objective of this study was to compare the effect of thermal and UV treatments on the content of antioxidants (phenolic acids, flavonoids, carotenoids, ascorbic acids) and antioxidant capacity of single strength pineapple juice. The antioxidants stability of juices throughout 14 days of refrigerated storage was also studied. Ultraviolet treatment shows higher ascorbic acid content after treatment as compared to thermally treated single strength pineapple juice. Storage time affected the studied antioxidants, where UV
treatment provided better stability to ascorbic acid content while thermal treatment provided better stability to flavonoids and carotenoids.