Effect of various cooking methods on antioxidant content and radical scavenging activity of pumpkin was evaluated. Pumpkin (Cucurbita moschata) was boiled and stir-fried for 2, 4 and 6 minutes respectively. Beta-carotene and lycopene were determined using HPLC and total phenolics measured using Folin-Ciocalteu method. The free radical scavenging activity of the samples was determined using 1, 1-diphenyl-2 picrylhydrazyl assay. Interestingly, result of the study showed an increase in both beta-carotene (2 to 4 times) and lycopene (17 to 40 times) content of pumpkin after cooking for 2, 4 and 6 minutes. However, the treatment resulted in 18 to 54% losses of total phenolics content of the pumpkin. Nevertheless, the free radical scavenging activity exhibited by cooked pumpkins was found to be high, in the range of 81.1% to 94.6% with IC50 of 1.41 to 1.62 mg ml-1
.
Consumption of repeatedly heated oil can be detrimental to health. The objective of this study was to determine the level of knowledge, attitude and practice of night market food outlet operators in Kuala Lumpur regarding the usage of repeatedly heated cooking oil. The quality of cooking oil was also investigated. A cross-sectional study involving pretested questionnaire was undertaken in April 2009. The questionnaire was designed as a tool to collect data from the respondents (n=100) by face-to-face interview. The results showed that majority of respondents had only moderate (53.0%) or low (18.0%) level of knowledge regarding this issue. Most respondents (67.0%) agreed that it is not a good practice. The majority (69.0%) agreed that the usage of repeatedly heated cooking oil is detrimental to health. Despite that, most respondents (63.0%) admitted that they had used cooking oil repeatedly. Most (62.0%) of the cooking oil samples taken from the night market food outlets were considered fit for human consumption. In conclusion, the level of knowledge of night market food outlet operators in Kuala Lumpur regarding this issue needs to be improved in order to ensure the safety of fried food purchased from such establishments.
Four formulations of burgers, prepared with 65% lean meat and 15% fat consisting of RBD palm stearin (PS), Socfat 4000P and Socfat 4100P and beef fat (BF) as control were evaluated for solid fat content (SFC), slip melting point (SMP), cooking loss, proximate analysis (moisture, fat and protein), colour, i.e. lightness ('L'), redness ('a') and yellowness ('b'), free fatty acid (FFA), iodine value (IV), thiobarbituric acid (TBA) and texture profile analysis (TPA). Sensory evaluation was carried out for texture, juiciness, aroma, oiliness and overall acceptance. SFC and SMP for raw and cooked SF4000P beef burgers were closest to BF control burgers, falling into the range of 35-40 degrees C. Cooking loss was highest for PS burgers, there were no significant differences (P > 0.05) amongst BF, SF4000P and SF4100P burgers. Proximate analysis on raw burgers showed SF4000P to contain high fat and lowest moisture contents. Objective textural measurements using texture profile analysis (TPA) for all cooked burgers showed no significant differences (P > 0.05) for springiness and cohesiveness. Variation of values among the formulations for hardness, gumminess and chewiness are explained by the differences of SFC for beef burgers with various types of fats. Raw and cooked PS burgers have the lightest 'L' values compared with other fat-substituted burgers while BF, SF4000P and SF4100P indicated no significant differences (P > 0.05) for 'L', 'a' and 'b' values. Beef fat showed the highest amount of free fatty acids (FFA) compared to palm oil samples. For the iodine value (IV), SF4000P showed the highest value which means that it contained the highest level of unsaturated fatty acids followed by PS, BF and SF4100P successively. SF4000P had the highest TBA values followed successively by BF, PS and SF4100P. For sensory evaluation, PS burgers had the least oily taste. This may be due to its high cooking loss. Taste panelists could not differentiate burgers with substituted vegetable fats against the control burgers.
In this study, various methods and applications of flat plate solar collectors are discussed and pictorial representations are presented. Low temperature applications of flat plate collectors are identified in solar cooking, solar water heating, space and air heating, industrial heating plants and in agricultural produce drying processes. Basic equations, as presented by many researchers in the performances of flat plate collectors, are also presented. The review discusses the analysis of losses from flat plate collectors towards obtaining the overall heat loss coefficient which indicate the performance of flat plate collectors.
Biodiesel side stream waste glycerol was identified as a cheap carbon source for rhamnolipids (RLs) production which at the same time could improve the management of waste. The present study aimed to produce RLs by using Pseudomonas aeruginosa RS6 utilizing waste glycerol as a substrate and to evaluate their physico-chemicals properties. Fermentation conditions such as temperature, initial medium pH, waste glycerol concentration, nitrogen sources and concentrations resulted in different compositions of the mono- and di-RLs produced. The maximum RLs production of 2.73 g/L was obtained when P. aeruginosa RS6 was grown in a basal salt medium supplemented with 1% waste glycerol and 0.2 M sodium nitrate at 35 °C and pH 6.5. At optimal fermentation conditions, the emulsification index (E24) values of cooking oil, diesel oil, benzene, olive oil, petroleum, and kerosene were all above E24=50%. The surface tension reduction obtained from 72.13 mN/m to 29.4-30.4 mN/m was better than the surface activity of some chemical-based surfactants. The RLs produced possessed antimicrobial activities against Gram-negative and Gram-positive bacteria with values ranging from 37% to 77% of growth inhibition when 1 mg/mL of RLs was used. Concentrations of RLs below 1500 μg/mL did not induce phytotoxicity effects on the tested seeds (Vigna radiata) compared to the chemical-based- surfactant, SDS. Furthermore, RLs tested on zebrafish (Danio rerio) embryos only exhibited low acute toxicity with an LC50 value of 72.97 μg/mL at 48 h of exposure suggesting a green and eco-biochemical worthy of future applications to replace chemical-based surfactants.
Consumers are reported to be increasingly concerned about their health. Nonetheless, consumers show different attitudes toward food at home and away from home. In particular, consumers tend to shy away from healthy food items when dining on special occasions. This study is the first to look into the number of healthy menu items provided to consumers during dining occasions. The impacts of two independent variables (dining occasion: normal vs. special; number of healthy items: limited vs. extended) on consumers’ dining menu selection was examined among female university students. The results of this study indicate that both dining occasion and the number of healthy items offered could influence consumers’ food selection independently. Although consumers are more likely to choose unhealthy items while dining’on special occasions, offering more healthy items would increase the probability of healthy eating. This study also offers some insights into the food categories and cooking methods favored by consumers. Further studies should explore other potential foods that would enhance the selection of healthy options by consumers.
Sauropus androgynus L. Merr. is one of the most popular herbs in South Asia, Southeast Asia, and China where it was known as a slimming agent until two outbreaks of pulmonary dysfunction were reported in Taiwan and Japan in 1995 and 2005, respectively. Several studies described that the excessive consumption of Sauropus androgynus could cause drowsiness, constipation, and bronchiolitis obliterans and may lead to respiratory failure. Interestingly, this herb has been used in Malaysia and Indonesia in cooking and is commonly called the "multigreen" or "multivitamin" plant due to its high nutritive value and inexpensive source of dietary protein. The plant is widely used in traditional medicine for wound healing, inducing lactation, relief of urinary disorders, as an antidiabetic cure and also fever reduction. Besides these medicinal uses, the plant can also be used as colouring agent in food. This review will explore and compile the fragmented knowledge available on the botany, ethnobotany, chemical constitutes, pharmacological properties, and toxicological aspects of this plant. This comprehensive review will give readers the fundamental, comprehensive, and current knowledge regarding Sauropus androgynus L. Merr.
Campylobacter jejuni was found to occur at high prevalence in the raw salad vegetables examined. Previous reports describe cross-contamination involving meat; here we investigated the occurrence of cross-contamination and decontamination events in the domestic kitchen via C. jejuni-contaminated vegetables during salad preparation. This is the first report concerning quantitative cross-contamination and decontamination involving naturally contaminated produce. The study was designed to simulate the real preparation of salad in a household kitchen, starting with washing the vegetables in tap water, then cutting the vegetables on a cutting board, followed by slicing cucumber and blanching (heating in hot water) the vegetables in 85 degrees C water. Vegetables naturally contaminated with C. jejuni were used throughout the simulation to attain realistic quantitative data. The mean of the percent transfer rates for C. jejuni from vegetable to wash water was 30.1 to 38.2%; from wash water to cucumber, it was 26.3 to 47.2%; from vegetables to cutting board, it was 1.6 to 10.3%; and from cutting board to cucumber, it was 22.6 to 73.3%. The data suggest the wash water and plastic cutting board as potential risk factors in C. jejuni transmission to consumers. Washing of the vegetables with tap water caused a 0.4-log reduction of C. jejuni attached to the vegetables (most probable number/gram), while rapid blanching reduced the number of C. jejuni organisms to an undetectable level.
Matched MeSH terms: Cooking/methods*; Cooking and Eating Utensils
Green leafy vegetables are good sources of carotenoids. Generally, food composition databases related to raw foods are available, but data on cooked foods in Malaysia are still lacking. Since carotenoids are prone to degradation during cooking processes, the present study was undertaken to evaluate the extent of nutrient loss in vegetables subjected to two conventional cooking methods, which were boiling and stir-frying with cooking durations of 4 and 8 minutes. The vegetables selected were Chinese cabbage (Brassica Pekinensis var. cephalata), swamp cabbage (Ipomoea aquatica), spinach (Spinacia oleracea), Ceylon spinach (Basella rubra), red spinach (Amaranthus gangeticus), white spinach (Amaranthus viridis) and tapioca shoots (Manihot utilissima). Percentage losses of nutrients after cooking treatment were calculated based on retention factors. Results obtained showed that stir-frying had reduced lutein content for all vegetables ranging from 8-89% while the effect of boiling for lutein varied (0-428%) with different vegetables at both cooking durations of 4 and 8 min. Boiling for 8 min increased retention of β carotene in all vegetables ranging from 18-380% except for Chinese cabbage and spinach compared with 4 min, while stir-frying generally increased the retention of β-carotene for all vegetables 2-3 times except for spinach. Cooked vegetables have variations in carotenoids composition brought by varying cooking conditions (time and temperature), type of vegetables and the interaction between cooking methods and type of vegetables.
Migration of melamine has been determined for 41 types of retail melamine-ware products in Malaysia. This study was initiated by the Ministry of Health, Malaysia, in the midst of public anxiety on the possibility of melamine leaching into foods that come into contact with the melamine-ware. Thus, the objective of this study was to investigate the level of melamine migration in melamine utensils available on the market. Samples of melamine tableware, including cups and plates, forks and spoons, tumblers, bowls, etc., were collected from various retail outlets. Following the test guidelines for melamine migration set by the European Committee for Standardisation (CEN 2004) with some modifications, the samples were exposed to two types of food simulants (3% acetic acid and distilled water) at three test conditions (25°C (room temperature), 70 and 100°C) for 30 min. Melamine analysis was carried out using LC-MS/MS with a HILIC column and mobile phase consisting of ammonium acetate/formic acid (0.05%) in water and ammonium acetate/formic acid (0.05%) in acetonitrile (95 : 5, v/v). The limit of quantification (LOQ) was 5 ng/ml. Melamine migration was detected from all samples. For the articles tested with distilled water, melamine migration were [median (interquartile range)] 22.2 (32.6), 49.3 (50.9), 84.9 (89.9) ng/ml at room temperature (25°C), 70 and 100°C, respectively. In 3% acetic acid, melamine migration was 31.5 (35.7), 81.5 (76.2), 122.0 (126.7) ng/ml at room temperature (25°C), 70 and 100°C, respectively. This study suggests that excessive heat and acidity may directly affect melamine migration from melamine-ware products. However the results showed that melamine migration in the tested items were well below the specific migration limit (SML) of 30 mg/kg (30,000 ng/ml) set out in European Commission Directive 2002/72/EC.
The method of liquid chromatographic tandem mass spectrometry was utilized and modified to confirm and quantify acrylamide in heating cooking oil and animal fat. Heating asparagine with various cooking oils and animal fat at 180°C produced varying amounts of acrylamide. The acrylamide in the different cooking oils and animal fat using a constant amount of asparagine was measured. Cooking oils were also examined for peroxide, anisidine and iodine values (or oxidation values). A direct correlation was observed between oxidation values and acrylamide formation in different cooking oils. Significantly less acrylamide was produced in saturated animal fat than in unsaturated cooking oil, with 366ng/g in lard and 211ng/g in ghee versus 2447ng/g in soy oil, followed by palm olein with 1442ng/g.
This work investigated the underlying formation of acrylamide from amino acids in frying oils during high temperatures and at different times via modeling systems. Eighteen amino acids were used in order to determine which one was more effective on acrylamide production. Significantly the highest amount of acrylamide was produced from asparagine (5987.5µg/kg) and the lowest from phenylalanine (9.25µg/kg). A constant amount of asparagine and glutamine in palm olein and soy bean oils was heated up in modelling system at different temperatures (160, 180 and 200°C) and times (1.5, 3, 4.5, 6, 7.5min). The highest amount of acrylamide was found at 200°C for 7.5min (9317 and 8511µg/kg) and lowest at 160°C for 1.5min (156 and 254µg/kg) in both frying oils and both amino acids. Direct correlations have been found between time (R2=0.884), temperature (R2=0.951) and amount of acrylamide formation, both at p<0.05.
Consumption of corn oil for cooking purpose is gaining popularity. The present study examined the effect of heated corn oil on blood pressure and its possible mechanism in experimental rats. Thirty male Sprague-Dawley rats were randomly divided into 5 groups and were fed with the following diets, Group I was fed with basal diet only; whereas group II,III,IV and V were fed with basal diet fortified with 15% (w/w) either fresh, once-heated, five-times-heated or ten-times-heated corn oil, respectively for 16 weeks. Body weight, blood pressure were measured at baseline and weekly interval for 16 weeks. Inflammatory biomarkers which included soluble intracellular adhesion molecules (sICAM), soluble vascular adhesion molecules (sVCAM) and C reactive protein (CRP), were measured at baseline and the end of 16 weeks. The rats were sacrificed and thoracic aorta was taken for measurement of vascular reactivity. There was significant increase in the blood pressure in the groups fed with heated once, five-times (5HCO) and ten-times-heated corn oil (10-HCO) compared to the control. The increase in the blood pressure was associated with an increase in CRP, sICAM and sVCAM, reduction in vasodilatation response to acetylcholine and greater vasoconstriction response to phenylephrine. The results suggest that repeatedly heated corn oil causes elevation in blood pressure, vascular inflammation which impairs vascular reactivity thereby predisposing to hypertension. There is a need to educate people not to consume corn oil in a heated state.
Food-handling practices were studied in 119 and 158 households, respectively, in an urban and a rural community in Peninsular Malaysia. Hazard analyses, including microbiological analysis of foods, were carried out in two households in each community and in a house that prepared food for distribution in the urban area. Kitchen hygiene was generally acceptable, although rated "poor" in some instances in the rural area. Food prepared for lunch was usually sufficient for dinner also, the leftover items being stored at ambient temperature until required. In the house that prepared food for distribution, breakfast was prepared during the evening, stored at ambient temperature overnight, and reheated before sale the next morning. There was a local preference for cooking food at temperatures close to boiling point; this reduced the numbers of vegetative cells but not those of spores. In some stored foods the populations of Staphylococcus aureus, Bacillus cereus and mesophilic aerobic bacteria increased, the last-mentioned reaching spoilage levels. Reheating reduced the populations of proliferating bacteria in most foods to acceptable levels but would not have destroyed heat-resistant enterotoxins. Because of their importance in combating acute bacterial foodborne disease, the control of the temperature and time factors during the cooking and storage of food should receive special attention in education on health and food safety.
Pork and bovine collagen incorporated into meat products showed promising
functional properties as food ingredients but has the halal issue. This study
investigated the effect of incorporating fish collagen hydrolysate (FCH) as a fat replacer
in buffalo patties in terms of proximate values, texture and colour properties. There
were five different formulations including a control (10% fat, 0% FCH), A (7.5% fat, 2.5%
FCH), B (5% fat, 5% FCH), C (2.5% fat, 7.5% FCH), and D (0% fat, 10% FCH). There were
no significant differences (p>0.05) between all formulations in terms of cooking yield,
shrinkage, water-holding capacity, and pH value. The sensory test showed no
significant difference (p>0.05) between all formulations in terms of colour,
appearance, juiciness, aroma, and overall acceptability, while sample D with 10% FCH
had significantly lower (p
Ulam or traditional vegetables in Malaysia comprise more than 120 species representing various
families ranging from groundcovers, shrubs to trees. The leaves, shoots, flowers, fruits, roots and rhizomes of the vegetables are eaten fresh as salad or cooked and are consumed to add variety and flavor to the diet, as well as for their health benefits. Ulam species are rich in carbohydrate, protein, mineral and vitamin. This study established that ulam species differ greatly with respect to types and concentrations of carotenoids in leaves. A total of 10 species were evaluated for quantitative and qualitative carotenoid composition through spectrophotometry and HPLC analysis. The main carotenoids identified in these selected ulam were lutein, neoxanthin, violaxanthin, zeaxanthin and β-carotene. The ratio of these carotenoids varies between species.
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.
The physical attributes (pH and colour), cooking yield, textural and mechanical properties (firmness, tensile and texture profiles analyses) and structural breakdown properties (multiple extrusion cell with added artificial saliva) of five yellow alkaline noodle (YAN) formulations were studied. Samples used were noodles with (a) typical formulation (control), (b) soy protein isolate (SPI), (c) soy protein isolate plus microbial transglutaminase enzyme (SPI/MTGase), (d) green banana pulp flour (GBPu) and (e) green banana peel flour (GBPe). Compared to other noodles SPI/MTGase noodle showed significantly (P < 0.05) higher values in terms of textural, mechanical and breakdown properties. Incorporating SPI, banana pulp and peel flours into the noodles had imposed some differences on most of the mechanical and textural parameters from the control YAN. However, these noodles could not be clearly distinguished in term of structural breakdown properties.
Conocarpus fiber is an abundantly available and sustainable cellulosic biomass. With its richness in cellulose content, it is potentially used for manufacturing microcrystalline cellulose (MCC), a cellulose derivative product with versatile industrial applications. In this work, different samples of bleached fiber (CPBLH), alkali-treated fiber (CPAKL), and acid-treated fiber (CPMCC) were produced from Conocarpus through integrated chemical process of bleaching, alkaline cooking, and acid hydrolysis, respectively. Characterizations of samples were carried out with Scanning Electron Microscope (SEM), Energy Dispersive X-ray (EDX), Fourier Transform Infrared-Ray (FTIR), X-ray Diffraction (XRD), Thermogravimetric (TGA), and Differential Scanning Calorimetry (DSC). From morphology study, the bundle fiber feature of CPBLH disintegrated into micro-size fibrils of CPMCC, showing the amorphous compounds were substantially removed through chemical depolymerization. Meanwhile, the elemental analysis also proved that the traces of impurities such as cations and anions were successfully eliminated from CPMCC. The CPMCC also gave a considerably high yield of 27%, which endowed it with great sustainability in acting as alternative biomass for MCC production. Physicochemical analysis revealed the existence of crystalline cellulose domain in CPMCC had contributed it 75.7% crystallinity. In thermal analysis, CPMCC had stable decomposition behavior comparing to CPBLH and CPAKL fibers. Therefore, Conocarpus fiber could be a promising candidate for extracting MCC with excellent properties in the future.