Acrylamide is a probable human carcinogen, and its presence in a range of fried and oven-cooked foods has raised considerable health concern world-wide. Dietary intake studies observed significant variations in acrylamide concentrations, which complicate risk assessment and the establishment of effective control measures. The objective of this study was to obtain an insight into the actual variation in acrylamide concentrations in French fries prepared under typical conditions in a food service establishment (FSE). Besides acrylamide, frying time, frying temperature, and reducing sugars were measured and the actual practices at receiving, thawing and frying during French fries preparation were observed and recorded. The variation in the actual frying temperature contributed most to the variation in acrylamide concentrations, followed by the variation in actual frying time; no obvious effect of reducing sugars was found. The lack of standardised control of frying temperature and frying time (due to inadequate frying equipment) and the variable practices of food handlers seem to contribute most to the large variation and high acrylamide concentrations in French fries prepared in a restaurant type of FSE as compared to chain fast-food services, and institutional caterers. The obtained insights in this study can be used to develop dedicated control measures in FSE, which may contribute to a sustainable reduction in the acrylamide intake.
Replacement of beef by buffalo and vice versa is frequent in global markets, but their authentication is challenging in processed foods due to the fragmentation of most biomarkers including DNA. The shortening of target sequences through use of two target sites might ameliorate assay reliability because it is highly unlikely that both targets will be lost during food processing. For the first time, we report a tetraplex polymerase chain reaction (PCR) assay targeting two different DNA regions in beef (106 and 120-bp) and buffalo (90 and 138-bp) mitochondrial genes to discriminate beef and buffalo in processed foods. All targets were stable under boiling, autoclaving and microwave cooking conditions. A survey in Malaysian markets revealed 71% beef curries contained buffalo but there was no buffalo in beef burgers. The assay detected down to 0.01ng DNA and 1% meat in admixed and burger products.
Vinegars are liquid products produced from the alcoholic and subsequent acetous fermentation of carbohydrate sources. They have been used as remedies in many cultures and have been reported to provide beneficial health effects when consumed regularly. Such benefits are due to various types of polyphenols, micronutrients and other bioactive compounds found in vinegars that contribute to their pharmacological effects, among them, antimicrobial, antidiabetic, antioxidative, antiobesity and antihypertensive effects. There are many types of vinegars worldwide, including black vinegar, rice vinegar, balsamic vinegar and white wine vinegar. All these vinegars are produced using different raw materials, yeast strains and fermentation procedures, thus giving them their own unique tastes and flavours. The main volatile compound in vinegar is acetic acid, which gives vinegar its strong, sour aroma and flavour. Other volatile compounds present in vinegars are mainly alcohols, acids, esters, aldehydes and ketones. The diversity of vinegars allows extensive applications in food.
A novel way to fully utilize rambutan fruit and seed is to ferment peeled fruits followed by drying and roasting, and use the seeds to produce seed powder similar to that of cocoa powder. Hence, the objective of this study was to optimize the roasting time and temperature of rambutan fruit post-fermentation and drying, and to produce a cocoa-like powder product from the seeds. Parameters monitored during roasting were colour and total phenolic content, while seed powder obtained using optimized roasting conditions was analyzed for its physicochemical properties and toxicity. The latter was examined using the brine shrimp lethality assay. Results showed that the roasted seed powder possessed colour and key volatile compounds similar to that of cocoa powder. Besides, the brine shrimp lethality assay indicated that the roasted seed powder was non-toxic. Thus, the fruit, including its seed could be fully utilized and subsequently, wastage could be reduced.
Rambutan seed is usually discarded during fruit processing. However, the seed contains a considerable amount of crude fat. Hence, the objective of this study was to investigate the fat properties and antinutrient content of the seed during fermentation of rambutan fruit. Results showed that the crude fat content of the seed reduced by 22% while its free fatty acid content increased by 4.3 folds after 10 days of fermentation. Arachidic acid was selectively reduced and was replaced by linoleic acid from the seventh day of fermentation onwards. Only 14.5% of triacylglycerol remained in the seed fat at the end of fermentation. The complete melting temperature, crystallization onset temperature and solid fat index at 37 °C of the fermented seed fat were higher than that of non-fermented seed fat. The saponin and tannin contents of the seed were reduced by 67% and 47%, respectively, after fermentation.
Linusorbs (LO), cyclolinopeptides, are a group of cyclic hydrophobic peptides and considered a valuable by-product of flaxseed oil due to numerous health benefits. Currently applied acetone or methanol extraction could contaminate the feedstocks for further food-grade application. Using flaxseed cake as feedstock, this study established a practical method for preparing LO from pressed cake. Firstly, LO composition of 15 flaxseed cultivars was analyzed. Next, cold-pressed cake was milled and screened mechanically. The kernel and hull fractions were separated based on the disparity of their mechanical strength. Monitored by hyperspectral fluorescence, the LO-enriched kernel fraction separated from cold-pressed flaxseed cake was further used as feedstock for LO production. After ethanol extraction, partition, and precipitation, LOs were extracted from cold-pressed flaxseed cake with a purity of 91.4%. The proposed method could serve as feasible flaxseed cake valorization strategy and enable the preparation of other polar compounds such as flax lignan and mucilage.
This study investigated the removal of bacterial surface structures, particularly flagella, using sonication, and examined its effect on the attachment of Salmonella Typhimurium ATCC 14028 cells to plant cell walls. S. Typhimurium ATCC 14028 cells were subjected to sonication at 20 kHz to remove surface structures without affecting cell viability. Effective removal of flagella was determined by staining flagella of sonicated cells with Ryu's stain and enumerating the flagella remaining by direct microscopic counting. The attachment of sonicated S. Typhimurium cells to bacterial cellulose-based plant cell wall models and cut plant material (potato, apple, lettuce) was then evaluated. Varying concentrations of pectin and/or xyloglucan were used to produce a range of bacterial cellulose-based plant cell wall models. As compared to the non-sonicated controls, sonicated S. Typhimurium cells attached in significantly lower numbers (between 0.5 and 1.0 log CFU/cm2) to all surfaces except to the bacterial cellulose-only composite without pectin and xyloglucan. Since attachment of S. Typhimurium to the bacterial cellulose-only composite was not affected by sonication, this suggests that bacterial surface structures, particularly flagella, could have specific interactions with pectin and xyloglucan. This study indicates that sonication may have potential applications for reducing Salmonella attachment during the processing of fresh produce.
Interesterification reaction involves rearrangement of the fatty acid radicals on the glycerol backbone, either randomly (chemical interesterification) or regioselectivity (enzymatic interesterification). Refined, bleached and deodourised palm oil (RBDPO) and palm kernel oil (RBDPKO) were blended in ratios from 25:75 to 75:25 (wt/wt). All blends were subjected to enzymatic (EI) and chemical interesterification (CI) using Lipozyme TL IM (4% w/w) and sodium methoxide (0.2% m/m) as the catalysts, respectively. The effect of EI and CI on the triacylglycerol (TAG) composition, thermal behaviour, polymorphism, crystal morphology and crystallisation kinetics were studied. The aim of this research is to characterise the nature of crystals in food product for certain desired structure. The crystallisation behaviour discussed in this study involves microstructure (PLM), polymorphism (XRD), thermal properties and crystallisation kinetics by DSC. The alteration in TAG composition was greater after CI as compared to EI with the reduction of LaLaLa (from 11.00% to 5.15%) and POO (from 14.28% to 4.87%). The DSC complete melting and crystallisation temperature of blend with 75% PO increased after CI, from 39.58 °C to 41.67 °C and from -30.84 °C to -28.33 °C, respectively. EI contributed to finer crystals than CI. However, the β' and β polymorph mixture and crystallisation kinetics (n = 2) of PO-PKO blends did not change after CI and EI. The knowledge on controlling crystallisation of RBDPO and RBDPKO blends is vital for proper processing condition like margarine production.
Rapeseed oil is the second most abundant produced edible oil in the world with low erucic acid and low glucosinolate. Thus, the quality of rapeseed oil had attracted global attention. Cold-pressed rapeseed oil appeared to be a preferred choice than refined oil as no solvent and less processing involved in the cold-pressing. The methods of cold-pressing and microwave pre-treatment on the extraction yield and bioactive compounds of rapeseed oil have been reviewed in this paper. Cold-pressed rapeseed oil offers health benefits due to its preserved fatty acid profile and bioactive compounds. High phenolic compounds, tocopherols, phytosterols, and carotenoids contents in the cold-pressed rapeseed oil offer health benefits like regulating blood lipid profile, insulin sensitivity, and glycemic control, as well as offer antioxidant and cytotoxic activity. Besides using as edible oil, cold-pressed rapeseed oil find applications in animal feed, chemical, and fuel.
Pineapple (Ananas comosus) is a tropical fruit that is highly relished for its unique aroma and sweet taste. It is renowned as a flavourful fruit since it contains a number of volatile compounds in small amounts and complex mixtures. Pineapple is also a rich source of minerals and vitamins that offer a number of health benefits. Ranked third behind banana and citrus, the demand for pineapple has greatly increased within the international market. The growth of the pineapple industry in the utilisation of pineapple food-based processing products as well as waste processing has progressed rapidly worldwide. This review discusses the nutritional values, physicochemical composition and volatile compounds, as well as health benefits of pineapples. Pineapple contains considerable amounts of bioactive compounds, dietary fiber, minerals, and nutrients. In addition, pineapple has been proven to have various health benefits including anti-inflammatory, antioxidant activity, monitoring nervous system function, and healing bowel movement. The potential of food products and waste processing of pineapples are also highlighted. The future perspectives and challenges with regard to the potential uses of pineapple are critically addressed. From the review, it is proven that pineapples have various health benefits and are a potential breakthrough in the agricultural and food industries.
As a protein-rich, underutilized crop, green soybean could be exploited to produce hydrolysates containing angiotensin-I converting enzyme (ACE) inhibitory peptides. Defatted green soybean was hydrolyzed using four different food-grade proteases (Alcalase, Papain, Flavourzyme and Bromelain) and their ACE inhibitory activities were evaluated. The Alcalase-generated green soybean hydrolysate showed the highest ACE inhibitory activity (IC50: 0.14 mg/mL at 6 h hydrolysis time) followed by Papain (IC50: 0.20 mg/mL at 5 h hydrolysis time), Bromelain (IC50: 0.36 mg/mL at 6 h hydrolysis time) and Flavourzyme (IC50: 1.14 mg/mL at 6 h hydrolysis time) hydrolysates. The Alcalase-generated hydrolysate was profiled based on its hydrophobicity and isoelectric point using reversed phase high performance liquid chromatography (RP-HPLC) and isoelectric point focusing (IEF) fractionators. The Alcalase-generated green soybean hydrolysate comprising of peptides EAQRLLF, PSLRSYLAE, PDRSIHGRQLAE, FITAFR and RGQVLS, revealed the highest ACE inhibitory activity of 94.19%, 99.31%, 92.92%, 101.51% and 90.40%, respectively, while their IC50 values were 878 μM, 532 μM, 1552 μM, 1342 μM and 993 μM, respectively. It can be concluded that Alcalase-digested green soybean hydrolysates could be exploited as a source of peptides to be incorporated into functional foods with antihypertensive activity.
An international survey among consumers in developing countries from Asia and Africa on food safety knowledge, attitudes and practices (KAP) was carried out using structured questionnaires. Data were collected from 453 consumers comprising 265 from Africa and 188 from Asia. Significant difference (p food safety knowledge attitude and practice between consumers from Africa and Asia was observed. In Africa, consumers in Cameroon had the least food safety knowledge (73.15 ± 16.43) compared to Ghana (78.19 ± 15.84) and Nigeria (88.16 ± 8.88). Similarly, consumers in Iran had the least food safety knowledge (73.33 ± 19.84) in Asia compared to Malaysia (88.36 ± 11.64) and Pakistan (89.42 ± 9.89). Among the respondents, 89% were aware of food poisoning while 304 (67.1%) consume food kept for long at room temperature. There was significant difference (p food safety knowledge, attitudes and practices of consumers between Africa and Asia. Overall, respondents from Asia have better food safety knowledge than respondents from Africa.
The substitution of milk fat with virgin coconut oil (VCO) was used to produce nutritious ice cream with pleasant coconut flavor and aroma. Three formulations were developed whereby formulation VCO4, VCO8 and VCO12 was substituted with 4%, 8% and 12% of VCO, respectively. The physicochemical properties of ice creams analyzed include overrun, meltdown, pH, titratable acidity, total solid, protein and fat content. The fatty acids profile of VCO formulated ice creams and their stabilities over 3 and 6 weeks storage were studied respectively using gas chromatography (GC). Qualitative descriptive analysis (QDA) and consumer affective test were performed among the trained and untrained panelists. Significant differences (p < 0.05) of overrun, pH, total solid, protein and fat content between ice cream formulations were observed except titratable acidity. Increased VCO content in ice cream formulations lowered the melting resistance of ice cream. For GC analysis, the major fatty acid identified was lauric acid. Upon storage time, the concentration of unsaturated fatty acid decreased but the concentration of saturated fatty acid increased. The result of QDA showed that formulation VCO4, VCO8 and VCO12 were significantly (p < 0.05) different in attributes of color, firmness and smoothness as compared to the control ice cream. Formulation VCO12 was highly accepted by panelists in terms of the acceptance level of appearance, aroma, texture, flavor and overall acceptability. Hence, it has a potential marketable value.
This study investigated the influence of pregelatinized high-amylose maize starch and chilling treatment on the physical and textural properties of canned rice noodles thermally processed in a retort. Rice noodles were prepared from rice flour partially substituted with pregelatinized high-amylose maize starch (Hylon VII™) in the ratios 0, 5, 10, and 15% (wt/wt). High-amylose maize starch improved the texture and brightness of fresh (not retorted) noodles. Chilling treatment led to significant (P ≤ 0.05) improvement in the texture of fresh noodles at all levels of substitution with high-amylose starch. The highest hardness was recorded at 15% amylose level in chilled nonretorted noodles. Retort processing induced a major loss of quality through water absorption, retort cooking loss, decreased noodle hardness, and lightness. However, the results showed that amylose and chilling treatment positively reduced the impact of retorting. For each level of amylose substitution, a low retort cooking loss and increased noodle hardness were associated with a chilling treatment. For both chilled and nonchilled noodles, retort cooking loss and hardness increased with increasing levels of amylose substitution.
This study was undertaken to evaluate the feasibility of using commercial starter cultures for quality improvement of spreadable processed cheese manufactured from ultrafiltered milk retentates. Compared to control, six samples of ultrafiltered milk retentate were incubated at 25 ℃ with starter cultures CHN-22, FRC-60, and ABT-8. Three samples were incubated for 24 h and the others were incubated for 72 h. Physicochemical, microbiological, and organoleptic characteristics in all treatments during the 90-day cold storage (6 ± 2 ℃) period were determined. The results showed that protein content of all treatments was significantly lower than the control. Utilization of starter cultures in ultrafiltered processed cheese production increased titratable acidity, where titratable acidity of the treatments (PC22-3, PC60-3, and PC8-3) was significantly higher than the other treatments and the control. PC8-1, PC60-1, and PC22-1 treatments were the highest penetrometer readings and with low firmness. All treatments had higher water soluble nitrogen/total nitrogen%, total bacterial viable and lactic acid bacterial counts especially PC22-3, PC60-3, and PC8-3 compared to the control. The results revealed that PC60-1 and PC22-3 treatments gained the highest acceptability scores than PC60-3, PC22-1, and the control.
Kenaf ( Hibiscus cannabinus L.) seed oil has been proven for its multi-pharmacological benefits; however, its poor water solubility and stability have limited its industrial applications. This study was aimed to further improve the stability of pre-developed kenaf seed oil-in-water nanoemulsions by using food-grade ternary emulsifiers. The effects of emulsifier concentration (1, 5, 10, 15% w/w), homogenisation pressure (16,000, 22,000, 28,000 psi), and homogenisation cycles (three, four, five cycles) were studied to produce high stability of kenaf seed oil-in-water nanoemulsions using high pressure homogeniser. Generally, results showed that the emulsifier concentration and homogenisation conditions had great effect ( p food and nutraceutical industries.
Strawberry puree was processed for 15 min using thermal (65 ℃), high-pressure processing (600 MPa, 48 ℃), and ultrasound (24 kHz, 1.3 W/g, 33 ℃). These conditions were selected based on similar polyphenoloxidase inactivation (11%-18%). The specific energies required for the above-mentioned thermal, high-pressure processing, and power ultrasound processes were 240, 291, and 1233 kJ/kg, respectively. Then, the processed strawberry was stored at 3 ℃ and room temperature for 30 days. The constant pH (3.38±0.03) and soluble solids content (9.03 ± 0.25°Brix) during storage indicated a microbiological stability. Polyphenoloxidase did not reactivate during storage. The high-pressure processing and ultrasound treatments retained the antioxidant activity (70%-74%) better than the thermal process (60%), and high-pressure processing was the best treatment after 30 days of ambient storage to preserve antioxidant activity. Puree treated with ultrasound presented more color retention after processing and after ambient storage than the other preservation methods. For the three treatments, the changes of antioxidant activity and total color difference during storage were described by the fractional conversion model with rate constants k ranging between 0.03-0.09 and 0.06-0.22 day - 1, respectively. In resume, high-pressure processing and thermal processes required much less energy than ultrasound for the same polyphenoloxidase inactivation in strawberry. While high-pressure processing retained better the antioxidant activity of the strawberry puree during storage, the ultrasound treatment was better in terms of color retention.
The effects of thermosonication on the quality of a stingless bee honey, the Kelulut, were studied using processing temperature from 45 to 90 ℃ and processing time from 30 to 120 minutes. Physicochemical properties including water activity, moisture content, color intensity, viscosity, hydroxymethylfurfural content, total phenolic content, and radical scavenging activity were determined. Thermosonication reduced the water activity and moisture content by 7.9% and 16.6%, respectively, compared to 3.5% and 6.9% for conventional heating. For thermosonicated honey, color intensity increased by 68.2%, viscosity increased by 275.0%, total phenolic content increased by 58.1%, and radical scavenging activity increased by 63.0% when compared to its raw form. The increase of hydroxymethylfurfural to 62.46 mg/kg was still within the limits of international standards. Optimized thermosonication conditions using response surface methodology were predicted at 90 ℃ for 111 minutes. Thermosonication was revealed as an effective alternative technique for honey processing.
The growth and survival of Salmonella typhimurium in goat milk samples at different shifting temperatures were evaluated. The growth of S. typhimurium at lower temperatures (5°C, 10°C, and 15°C) exhibited bacteriostatic effects in milk, whereas at ambient temperature (25°C) and at 45°C, this pathogen luxuriantly grew throughout the 12-h stationary phase. At 50°C this pathogen was found to be thermotolerant and could still thrive in the milk. Overall, shifting temperatures from 37°C to 55°C and 60°C clearly indicated S. typhimurium to have reached complete elimination. The results demonstrated that the adaptation and survival of this pathogen directly depend on temperature stress. It is expected that the results will be useful to dairy industries for implementation of good manufacturing practices with a better hazard analysis critical control point approach to predict the microbial risk assessment and also benefit the consumers.
Fresh raw shrimps were dipped for 10, 20, and 30 min at room temperature (25°C ± 1°C) in lactic acid (LA; 1.5%, 3.0%, v/v) to evaluate their antipathogenic effects against Vibrio cholerae, Vibrio parahaemolyticus, Salmonella entreitidis, and Escherichia coli O157:H7 inoculated at a level of 10(5) CFU/g. Significant reductions in the population of all these pathogenic bacteria were recorded after dipping treatments, which were correlated to the corresponding LA concentrations and treatment time. With respect to the microbial quality, 3.0% LA treatment for 10 min was acceptable in reducing the pathogenic bacteria. Additionally, sensory evaluation results revealed a 10-min dip in 3.0% LA to be more acceptable organoleptically compared with 20 and 30 min of treatments. Results of the present study are envisaged to be useful for commercial applications for effective decontamination of shrimp.