Nowadays, stingless bee honey (meliponine honey) or locally known as ‘madu lebah kelulut’ is becoming popular among Malaysian consumers due to its acclaimed health benefits and advantages such as antioxidant and anti-inflammatory activities. Usually, stingless bee honey is used as a supplement to modern medicine, and the increase in health awareness among consumers has also increased the demand for stingless bee honey. However, due to the low production of stingless bee honey in the local market, Malaysia continues to import honey from other countries. As there is an abundant of imported honey products, local beekeepers are facing stiff competition, and consumers also need to make a difficult purchasing decision on the most preferable honey products in the market. Therefore, the main objective of the present work was to determine the consumers’ quality preferences towards stingless bee honey based on sensory characteristics. A total of 406 respondents of honey consumers were selected to test stingless bee honey sample based on its appearance, aroma, texture and flavour. The respondents responded based on a structured questionnaire using a 5-point Likert scale statements about their responses towards stingless bee honey sensory characteristics. The responses of the respondents were analysed based on descriptive analysis, factor analysis and logistic regression analysis. The results revealed nine factors that influenced consumers’ preferences towards stingless bee honey such as granularity, colour, bitterness, sweetness, viscosity, spice aroma, sourness, herbal aroma and fruity aroma, with viscosity being the most influential factor. The present work concluded that sensory characteristics were important to determine the consumers’ quality preferences towards stingless bee honey on purchasing decision.
The aim of the present work was to produce a new soy milk-based cake. Soy milk was added at different percentages (0, 25, 50, 75, and 100%) during cake making to replace milk. Nutritional composition, batter characteristics, physical, and sensory properties, as well as the stability of cake during storage, were investigated. Sensory results indicated that cake with 50% soy milk had the most favourable acceptance scores with the highest score in the aroma, colour, and taste attributes. The addition of soy milk up to 50% produced a cake with higher protein content and lower carbohydrate content, along with lower density and higher specific volume compared to control. Cake with 50% soy milk addition had lower microbial counts as compared to control. Therefore, soy milk has the potential to act as a milk replacer in cake production.
Coconut oil (CNO) is a vegetable fat that can be applied as a cocoa butter substitute (CBS) due to its similar physical characteristics to cocoa butter. However, it must be fractionated or hydrogenated to be used as CBS. The aims of the present work was to fractionate CNO using supercritical fluid extraction (SFE), and determine the potential fraction which is suitable as CBS. CNO was fractionated by SFE at 48.3 MPa and 80°C into four different fractions, F1, F2, F3 and F4. Fraction 1 had the highest yield (48.9%) as compared to the other fractions. Fraction 4 had the lowest content of lauric acid, C12 (31.12%) and the highest amount of palmitic acid, C16 (16.43%); stearic acid, C18:0 (4.99%); and linoleic acid, C18:1 (17.44%). Fraction 4 also had the highest melting profile (25.24°C) and amount of solid fat content (state) closest to CB. Therefore, F4 was selected as a potential fraction for the application of CBS. This finding reveals that CNO can be fractionated by SFE and applied as CBS to help diversify the application of coconut products.
The present work investigated the effect of replacing a fraction of cocoa butter with limonene on fat crystallisation and bloom in the models of limonene-cocoa butter blends and seeded dark chocolate. Limonene was incorporated at a maximum of 6.7% (w/w) of cocoa butter in both types of samples, and were stored at 20 and 29°C changing cyclically every 12 h. Samples were analysed at weekly intervals up to three weeks, and the analysis was carried out by colour measurement for the whiteness index to detect bloom, and by X-ray diffraction (XRD) for crystal phase determination. DSC analysis was also carried out to assess the melting behaviour in the samples of the dark chocolate model. While the white colour of cocoa butter limited the bloom detection by colour, a large increase in whiteness index was recorded for the chocolate models. The XRD revealed an acceleration of crystal phase transformation in both types of samples. The changes in the melting behaviour for the dark chocolate model showed that the increased amount of limonene had caused the decrease in melting temperature. Hence, for practical applications, it can be suggested that the use of limonene, either as flavouring or for viscosity reduction in chocolate, can potentially result in increased bloom formation due to its effect on cocoa butter crystallisation and polymorphism transformation rate.
Lard adulteration in processed foods is a major public concern as it involves religion and
health. Most lard discriminating works require huge lab-based equipment and complex sample
preparation. The objective of the present work was to assess the feasibility of dielectric
spectroscopy as a method for classification of fats from different animal sources, in particular,
lard. The dielectric spectra of each animal fat were measured in the radio frequency of 100
Hz – 100 kHz at 45°C to 55°C. The fatty acid composition of each fat was studied by using
data from gas chromatography mass spectrometry (GCMS) to explain the dielectric behaviour
of each fat. The principal component analysis (PCA) and artificial neural network (ANN)
were used to classify different animal fats based on their dielectric spectra. It was found that
lard showed the highest dielectric constant spectra among other animal fats, and was mainly
affected by the composition of C16 and C18 fatty acids. PCA classification plot showed clear
performance in classifying different animal fats. Finally, ANN classification showed different
animal fats were classified into their respective groups effectively at high accuracy of 85%.
Dielectric spectroscopy, in combination with quantitative analysis, was concluded to provide
rapid method to discriminate lard from other animal fats.
In the present work, supercritical fluid extraction (SFE) with CO2 as solvent and EtOH/water (v/v) as co-solvent was optimised by applying 23 factorial experimental design for the extraction of betacyanins from red pitaya fruit (Hylocereus polyrhizus) peel. Three independent variables of pressure (20-30 MPa), temperature (40-60°C) and co-solvent concentration (10-20%) were chosen for response variables. With the 2 mL/min flow rate of CO2, the dynamic time of extraction was found to be 90 min. The linear effects of main factors and interactions were evaluated. The calculated response surface model for the pressure/temperature was found to be significant for all the dependent variables. At optimal condition of SFE, the response variables were assessed as maximum extraction yield of 4.09 ± 0.69%, total betacyanins content of 25.49 ± 1.54 mg/100 mL, redness (a*) of 58.18 ± 0.82, and IC50 (antioxidant activity) of 1.34 ± 0.12 mg/mL for the experimental peel extracts. The optimal levels of independent variables were validated for the experimental responses as predicted by the mathematical model. The reliability of this method was confirmed as there was no significant difference between experimental and predicted values. The HPLC-MS profile of betacyanins extract comprised of both acylated and non-acylated betacyanins constituents.
Piper cubeba L. is traditionally recognised as flavouring ingredient in various types of foods and has been used to marinate meat. Scientifically, it has been reported to possess various valuable nutritional and pharmacological properties including antimicrobial potential. The aim of the present work was to determine the antibacterial activity of ethanolic P. cubeba L. extract against Escherichia coli and its effect on the microbiological quality of raw chicken meat during storage. Disc diffusion assay was done and resulted in 8.40 ± 0.10 mm of inhibition zone. The bacteriostatic and bactericidal effects of the extract were determined at 0.63 ± 0.00 mg/mL and 1.25 ± 0.00 mg/mL of concentration by MIC and MBC methods, respectively. The killing time was recorded at 2 × MIC (1.25 mg/mL) for 4 h. The application of the extract on chicken meat samples showed reduction in TPC and E. coli count with the observed optimum condition at 5.00% concentration stored at -18°C for 14 days based on the consistent reduction. Sensory attributes acceptability evaluation by 9-point hedonic scale showed acceptable score for colour, odour, texture and overall acceptability of the treated raw chicken meat samples. The findings implies that P. cubeba L. can be listed as one of the alternatives to reduce the bacterial load of raw chicken meat prior to cooking which is very important in ensuring food safety as well as reducing the occurrence of foodborne poisoning associated with chicken meat.
Fennel (Foeniculum vulgare Mill.) and coriander (Coriandrum sativum L.) are known to possess good antimicrobial properties. In the present work, spice-infused frozen parathas were formulated to investigate the effect of fennel and coriander on microbial (aerobic mesophilic bacteria, yeast and mould, and Bacillus cereus) reduction and sensory acceptability of frozen paratha throughout the storage at -18°C. The present work was also aimed at determining the relationship between spice concentrations and storage durations on microbiological quality of the samples. Fennel and coriander seed powder were used at concentrations of 2, 4 and 6% of wheat flour (w/w). The microbiological analysis was performed by total plate count, yeast and mould count, and Bacillus cereus count after 9, 12 and 15 weeks of storage. Sensory evaluation was conducted using hedonic scales at the end of storage durations. Results showed that spice infusion in frozen paratha significantly delayed the growth of aerobic mesophilic bacteria, yeasts and moulds, and Bacillus cereus during storage. The lowest log count was demonstrated by coriander at 6% in total plate count (3.85, 3.90 and 3.91 log10 CFU/g), and yeast and mould count (2.54, 2.59 and 2.60 log10 CFU/g) after 9, 12 and 15 weeks, respectively. Bacillus cereus was not detected throughout the storage durations. Fennel exhibited minimum activity against Bacillus cereus with no significant difference on log count reduction when compared with control. Coriander showed the highest decrease in both total plate count and Bacillus cereus count during the storage duration. Sensory evaluation result indicated that control sample exhibited the highest preference over all attributes when compared with fennel and coriander. Coriander-infused paratha was slightly darker in colour due to high concentration of 6%. Fennel yielded the lowest score in terms of taste among all samples. Fennel and coriander showed no significant difference for sensory acceptability. Overall, all frozen parathas were in good quality after 15 weeks of frozen storage. It can thus be concluded that fennel and coriander can be used as potential natural preservatives to inhibit the growth of microorganisms in paratha during frozen storage. Nevertheless, the optimum spice concentration should be determined to minimise the effects on the sensory attributes.
Chicken skin gelatin hydrolysates and peptides with angiotensin converting enzyme inhibitory (ACEI) activity were produced enzymatically using alcalase, pronase E, and collagenase before fractionation into
Extracts from ‘kesinai’ (Streblus asper) leaves were investigated as a potential source of enzymes that can serve as an alternative to calf rennet in cheese making. Different types of extraction buffers were investigated namely sodium acetate buffer (pH 4.2-5.0), phosphate buffer (pH 6.0-7.0) and Tris-HCl buffer (pH 7.0-9.0). Finally, the milk-clotting enzyme was extracted using 100 mM Tris-HCl buffer (pH 7.4) with and without 5.0 mg/mL polyvinylpyrrolidone, 0.015 mL/mL Triton X-100 and 2 mM sodium metabisulphite. Purification was carried out using acetone precipitation, and ion-exchange and size-exclusion chromatographic techniques. Results showed that 100 mM Tris-HCl buffer (pH 7.4) was the most efficient extraction buffer among the buffers used in the extraction study. After the final purification step of size-exclusion chromatography, the enzyme was purified 3.3-fold with 42.3% of recovery. The enzyme showed an optimum temperature and pH at 60°C and pH 7.4, respectively. The enzyme was stable up to 70°C for one hour and the partially purified enzyme retained 83% and 96% of its original activity at pH 6.0 and 8.0, respectively. The molecular weight of the partially enzyme was estimated to be 75.8 kDa on SDS-PAGE. The milk-clotting activity of ‘kesinai’ enzyme was found to be lower than that of commercial Mucor rennet.
The present work was aimed to investigate the effect of drying methods (oven drying, foam mat drying) and temperatures (40°C, 60°C) on the nutritional characteristics of red- and yellow-watermelon rinds. It was found that foam mat drying produced the best results for preserving the most nutrients as compared to the conventional oven drying for both red- and yellow watermelon rinds. Temperature is a significant parameter that affects the nutritional characteristics of watermelon rinds powder for both methods. Finding suggests that foam mat drying at 40°C was the best method for producing watermelon rinds powder as it requires shorter treatment time and gave the best retention of protein and carbohydrate.
In the present work, the biogenic amines tryptamine (TRP), putrescine (PUT), histamine (HIS), tyramine (TYR) and spermidine (SPD) were determined in 32 various types of tofu that were obtained from different states in Malaysia. Three main types of tofu; soft tofu, firm tofu and processed tofu, were analysed in the present work. The biogenic amine contents in the respective types of tofu were analysed by a reversed-phase HPLC with a DAD detector after the aqueous extraction and derivatisation with dansyl chloride. The LOD values ranged from 0.019 mg/L for PUT to 0.028 mg/L for TYR. While, the LOQ values ranged from 0.063 mg/L (PUT) to 0.096 mg/L (TYR). The recovery values for all the five amines ranged from 80.3% to 120.5% with RSD ≤ 3.1%. The total levels of biogenic amines found varied, ranging from 1.5 mg/kg to 687.9 mg/kg, with mean values (p < 0.05) in descending order of 44.6, 12.6, 9.1, 4.8 and 4.7 mg/kg for PUT, TYR, SPD, HIS and TRP, respectively. PUT and TRP were the most prevailing biogenic amines and they were found respectively in 90.62% of the tofu analysed. Significant positive correlations (r = 0.266 to 0.874, p < 0.05) were found between some individual biogenic amines and protein content in all the three types of tofu. However, negative correlations (r = -0.246 to -0.832, p < 0.05) were observed between biogenic amines and moisture content, and between biogenic amines and water activity in all the three types of tofu. Significant and strong correlations (r = 0.525 to 0.999, p < 0.05) were found between most of the individual biogenic amines and the total biogenic amines. Those tofu exceeding the legal limits may affect the health of sensitive individuals.
The effects of four marination methods (water, papaya leaves juice, papaya leaves powder, and commercial meat tenderizer) on the meat quality and sensory attributes of cooked (moist and/or grill) Pectoralis major muscle of spent chicken were examined. Pectoralis major muscles from 40 spent chickens were assigned to four marination methods: marinating with 100 mL distilled water, Control (T1) (n = 10); marinating with papaya leaves juice (50 g PLP + 100 mL distilled water), T2 (n = 10); marinating with 50 g papaya leaves powder, T3 (n = 10); and marinating with 50 g commercial meat tenderizer, T4 (n = 10). Results of meat quality revealed the lowest drip loss, cooking loss, and shear force values of samples from T3 as compared to the other treatments. Additionally, myofibril fragmentation index of marinated Pectoralis major muscle from T3 was significantly higher than the other treatments. Among the treatments within the moist cooking method, T3 presented significantly higher scores for tenderness and juiciness and significantly lower score for flavour as compared to T1 and T2. In the grill cooking method, the highest scores for tenderness and juiciness were significantly demonstrated by samples of T2 and T3. Furthermore, samples from T2 had significantly higher score for flavour. Results of the present work demonstrated that marinating spent chicken meat with 50 g papaya leaves powder improved its tenderness and water holding capacity. Furthermore, greater improvement in tenderness and juiciness were observed when meat samples marinated with papaya leaves powder (T3) were further subjected to moist cooking method.
The optimum combination of Musa paradisiaca (MP) and Trigona sp. Honey (TH) in formulating high antioxidant jelly was analysed for total carbohydrate content (CHO), antioxidant capacity (AC), and acceptability via the Response Surface Methodology. Central composite design was employed to optimise the combination effect of two independent variables; namely MP (X1: 20-100%) and TH (X2: 20-100%) on the recovery of three responses; total carbohydrate content (Y1), antioxidant capacity (Y2), and acceptability (Y3). A polynomial model generated a satisfactory fitting of the experimental data with regards to total carbohydrate content (R2
= 0.8974, p < 0.0024), total antioxidant capacity (R2 = 0.9702, p < 0.0001), and acceptability (R2 = 0.9136, p < 0.0001). The optimum combination for maximum recovery of CHO, AC and acceptability were 20% of MP and 20% of TBH, with a predicted CHO of 33 Kcal/5 g, AC of
0.34 nm and acceptability score of 6.16 (< 5: not accepted; > 5: accepted).
The aim of the present work was to develop legume-based kefir yogurts to replace conventional dairy yogurts that are not suitable to be consumed by vegetarians and consumers who have lactose intolerance and milk allergy. Soy and black bean milk were incubated at 15°C and 20°C for 24 h with 35 g of water kefir grains to produce kefir yogurt. The proximate composition, physico-chemical and microbiological characteristics of the yogurts were evaluated. At 20°C, soy and black bean milk produced kefir yogurts with significantly lower pH, total soluble solids, and sucrose concentration, indicating that fermentation process carried out at 20°C had higher efficiency than 15°C; meanwhile, black bean milk produced better kefir yogurts than soymilk. Black bean kefir yogurt which was fermented at 20°C had higher level of total plate count (2.05 × 107 CFU/mL), yeast and mould count (6.95 × 106 CFU/mL), and lactobacilli count (8.3
× 105 CFU/mL) as compared to other kefir yogurts. In general, 20°C produced kefir yogurt with better technological properties. Both soymilk and black bean milk were good alternative substrates for kefir yogurt production.
The present work was carried out to formulate a pasta with oyster mushroom flour (OMF), and to evaluate the effect of its addition on the nutritional compositions, physicochemical properties, and sensorial acceptability of the formulated pasta. Four pasta formulations with different levels of OMF (0%, 5%, 10%, and 15%) were developed prior to the determination of the nutritional composition, physicochemical properties, and sensorial acceptability. Proximate components such as protein, ash, and fat increased with increasing OMF levels except for carbohydrates and energy, which were decreased with increasing OMF levels. Lightness (L*) and yellowness (b*) significantly decreased with increasing OMF levels, while redness (a*) increased with increasing OMF levels. The results showed that the optimum cooking time, elasticity, firmness, and shear work decreased with increasing OMF levels, while there were no significant differences in hardness or adhesiveness between the samples. In sensory evaluation, the pasta fortified with up to 10% OMF was generally well accepted by the sensory panellists. The addition of 10% OMF into the pasta resulted in an increase in its nutritional values, thus affecting its physicochemical properties, and improving some of its sensorial attributes.
The physico-chemical and antioxidant activity of the mesocarp and exocarp of Borassus flabellifer were determined to assess the potential of the fruit as a food ingredient. Proximate analysis indicated that both mesocarp and exocarp had a high fibre content of 23.92% and 28.20%, respectively, of which 62.5% and 79.4% were insoluble dietary fibre. The soluble dietary fibre was < 0.50% for both samples. Hemicellulose was the major component in the exocarp followed by cellulose and lignin. Meanwhile for the mesocarp, cellulose was the highest component followed by hemicellulose and lignin. Fructose, galactose, glucose, mannose and sucrose were detected in both samples. Phenol and tannins were present in both mesocarp and exocarp; however, saponin was only detected in the mesocarp. Radical scavenging activity (157.05 mM TE/g) and reducing power (213.05 mM Fe2+) of the exocarp were significantly higher as compared to those of the mesocarp.
The awareness of the general public on healthy foods has been a major concern and people are looking for the right variety of rice for diabetic patients. High amylose content rice with low glycaemic index (GI), which is an indicator of sugar release in the blood, is beneficial for human health. The present work was aimed to determine the physicochemical characteristics and nutritional compositions of MR219 mutant rice, and the effects of amylose content to blood glucose response and glycaemic index in field condition. A total of 31 M4 mutant lines (ML1 to ML31) were evaluated for physicochemical characteristics and nutritional compositions in comparison with the parental variety, MR219. In glycaemic response study, 48 female BALB/c mice were fed with glucose (a baseline), saline water, two check varieties (MR219 and MRQ74) and four selected mutant lines with different amylose contents. The physicochemical and proximate analysis revealed highly significant differences among the mutant lines. Some mutant lines improved amylose content and nutritional composition. Mutant ML3 had slightly higher amylose content than the parental variety and was recommended for glycaemic responses. However, the field experiment results showed two mutant lines namely; ML3 and ML30, having significantly lower glucose reading (5.49 mmol/L and 5.47 mmol/L, respectively) as compared to the parental variety and other mutant lines. The glucose level was found highest at 60 min after feeding but significantly dropped at 120 min. The normal glucose reading in ML3 and ML30 also resulted in moderate GI values (65% and 66%, respectively). As low and moderate GI foods are recommended for diabetic patients, ML3 and ML30 had high potential for their consumption, and can be suggested for further breeding program to develop low GI rice.
The present work assessed the effect of solid-state fermentation (SSF) and drying methods [hot air drying (HAD) and hot air drying assisted by microwave finish drying (MFD)] on the physicochemical, functional and gelatinisation properties of flours of Nangka and Tanduk plantain cultivars. Drying methods and SSF did not affect the fat, dietary fibre and carbohydrate contents of the plantain flours. However, both treatments significantly affected the pH and titratable acidity of the flours. In addition, SSF coupled with MFD significantly increased the water absorption and oil absorption capacities of the flours more than the flours obtained from the hot air drying. Similar trend was observed with the swelling characteristics of the flours. Fermented and MFD flours had higher swelling power than flours obtained by hot air drying. Optical microscopy revealed that drying methods employed in the present work did not significantly alter the starch granules birefringence of the plantains.
The present work was aimed to optimise the supercritical carbon dioxide extraction of dabai oil
from dabai pulp and defatted pulp using RSM in comparison with hexane extraction method.
Fatty acid profile and antioxidant properties of the extracted dabai oil were also determined.
Optimal RSM conditions were 36 MPa pressure, 40°C temperature and 21 min of extraction
time. The extracted yields ranged between 14.13% and 15.42%. Supercritical carbon dioxide
extracted oils had lower total phenolics, total flavonoids, and antioxidative activities than the
hexane-extracted oils. High-performance liquid chromatography results showed that only
vanillic, protocatechuic and gallic acids were identified in both hexane and supercritical carbon
dioxide extracted oils of defatted dabai pulp. The total saturated fatty acids were higher in
hexane-extracted dabai oil as compared to the supercritical carbon dioxide extracted oil, and
vice versa for the unsaturated fatty acid. Although supercritical carbon dioxide extracted dabai
oils are inferior to the hexane-extracted oils, they are preferred as they are extracted using
green technology.