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Kenaf (Hibiscus cannabinus) is an industrial crop in Malaysia, and especially used as a source for composite wood. Kenaf leaves as a by-product of the plantation can be consumed as food due to its high nutritional value. Kenaf leaves have high antioxidant properties, thus are suitable to be made into herbal tea. However, its flavour is considered sour, thus presenting a challenge for product development. The main objective of the present work was to evaluate the physicochemical and functional (ascorbic acid content, calcium content, and anti-diabetic) properties of kenaf leave tea (KLT) with 0, 60, and 100% kenaf leaves used. KLT was prepared by steaming and drying the kenaf leaves, followed by sieving. Then, the powder was mixed with distilled water at 1% (w/v). Another portion of red dates and goji berries tea (RGT) was prepared by boiling the red dates:goji berries:water at 1:2.5:28.5 ratio. Two portions of tea were infused using 60% KLT and 40% RGT. Results showed that a 100% KLT (positive control) was always highest in terms of total phenolic content (TPC) and total flavonoid content (TFC). The antioxidant activities were positively correlated with DPPH and ABTS scavenging activities, and ferric reducing antioxidant power (FRAP). Contrary, the negative control (0% KLT) showed the highest α-amylase inhibitory effect. The present work also evaluated the acceptance of consumers using the Hedonic sensory test among 50 panellists with balance male and female candidates. Since 100% KLT extract was in low pH values (2.17 ± 0.26), 60% KLT infused with goji berries and red dates gained the highest consumers' acceptance. Therefore, as a compromise between sensory and functional properties, a maximum of 60% KLT was a suitable formulation for the consumers.

The effects of homogenization cycles on the kenaf seed oil (KSO) emulsion stability was checked in this study. KSO nanoemulsions were prepared using a high-pressure homogenizer at 1, 3, and 5 cycles. Results showed that higher homogenization cycles provided the samples with a significant (p ≤ 0.05) smaller size of KSO droplets, but slightly disturbed the polydispersity index (PDI) and reduced (p ≤ 0.05) the zeta potential. All samples were within nano size (78.05—111.5 nm) and one high-pressure homogenization cycle treatment was chosen to proceed to the storage study. Over 28 days of storage at 4 and 30 °C, results showed that KSO nanoemulsion degradation was gradual in terms of increasing oxidation, droplet size, and PDI. There was no creaming and minimal flocculation until 21 days storage. The 30 °C storage maintained KSO emulsion at smaller droplet sizes, with minimal flocculation which was due to narrower PDI and higher zeta potential. Briefly, one cycle of high-pressure homogenization was sufficient to produce a stable KSO nanoemulsion, which was in small droplets, and physically stable during 28 days storage at 30 °C.

The present work demonstrated a method to determine the growing activities of typical soy sauce fermentation yeasts under sonication stimulation in stress and/or enriched conditions. The yeast activities were determined using a programmed spectrophotometer which automatically records the optical density (OD) of the growth media. The increasing OD values were directly proportionally to the amount of yeast cells within the growth media. Spectrometry method provides a typical sigmoidal curve with the lag time, maximum growth rate, and average growth rate of microorganisms. Activities of two industrial yeast strains (Zygosaccharomyces spp. and Candida spp.) under sonication stimulations (0.5 cycles, 60 amplitude) at different salt contents (1, 3, and 5%), glucose contents (5, 10, and 15%), sonication durations (10, 20, and 30 min), and incubation temperatures (30 and 37°C) were investigated in a 24-h growth cycle model system by one-factor-at-a-time (OFAT) design. Overall, sonication treatment in the presence of salt was not lethal to yeast cells. The maximum growth rate of both yeast strains was significantly reduced (p < 0.05) when the sample was treated with 5% salt content coupled with sonication. However, when the sample was further enriched with glucose at 10%, it yielded significantly highest growth rate (0.1310 ± 0.0107 OD/h). Finally, 10 min sonication and 30°C incubation temperature were found to be better as compared to the other treatment combinations. Sonication did not exert any detrimental effect on investigated yeasts, and stimulated the growth when enrichment was appropriately provided.

Deep-frying is a popular food preparation method although oxidized oil may be a health hazard. Minor components in frying oil including antioxidants like tocopherols and tocotrienols, fatty acid composition, triacylglycerol (TAG), and vitamins serve to protect vegetable oil from thermal deterioration. The eating habits of three ethnicity in Malaysia due to influence from the West was briefly mentioned. The importance of fats and oils, as well as the characteristics of each plant oil, were also explained in this project paper. A total of 31 studies fulfilled our inclusion criteria. Studies with humans and animals were accepted and included in this Meta-analysis. The probability of occurrence of obesity, atherosclerosis, hypertension, Type 2 diabetes, and oxidative stress were checked. The overall weighted mean differences for palm oil (PO), canola oil (CNO), corn oil (CO), extra virgin olive oil (EVOO), sunflower oil (SFO), and soybean oil (SBO) were 0.18 [95% CI: 0.11, 0.25; P < 0.00001], 5.50 [95% CI: 4.12, 6.87; P < 0.00001], 0.62 [95% CI: -4.71, 5.95; P = 0.82], 1.13 [95% CI: 0.39, 1.87; P = 0.003], -3.79 [95% CI: -5.61, -1.97; P < 0.00001], 0.46 [95% CI:0.29, 0.64; P < 0.00001] respectively. In short, this study revealed that there was no strong relationship found between a heated and/or repeated heated vegetable oil with the adverse health complications included based on current meta-analysis.

The detection of 3- and 2-MCPD ester and glycidyl ester was transformed from selected ion monitoring (SIM) mode to multiple reaction monitoring (MRM) mode by gas chromatography triple quadrupole spectrometry. The derivatization process was adapted from AOCS method Cd 29a-13. The results showed that the coefficient of determination (R2) of all detected compounds obtained from both detection mode was comparable, which falls between 0.997 and 0.999. The limit of detection and quantification (LOD and LOQ) were improved in MRM mode as compared to SIM mode. In MRM mode, the LOD of 3- and 2-MCPD ester was achieved 0.01 mg/kg while the LOQ was 0.05 mg/kg. Besides, LOD and LOQ of glycidyl ester were 0.024 and 0.06 mg/kg respectively. A blank spiked with MCPD esters (0.03, 0.10 and 0.50 mg/kg) and GE (0.06, 0.24 and 1.20 mg/kg) were chosen for repeatability and recovery tests. MRM mode showed better repeatability in area ratio and recovery with relative standard deviation (RSD %)

The technique of Fourier transform infrared spectroscopy is widely used to generate spectral data for use in the detection of food contaminants. Monochloropropanediol (MCPD) is a refining process-induced contaminant that is found in palm-based fats and oils. In this study, a chemometric approach was used to evaluate the relationship between the FTIR spectra and the total MCPD content of a palm-based cooking oil. A total of 156 samples were used to develop partial least squares regression (PLSR), artificial neural network (nnet), average artificial neural network (avNNET), random forest (RF) and cubist models. In addition, a consensus approach was used to generate fusion result consisted from all the model mentioned above. All the models were evaluated based on validation performed using training and testing datasets. In addition, the box plot of coefficient of determination (R2), root mean square error (RMSE), slopes and intercepts by 100 times randomization was also compared. Evaluation of performance based on the testing R2 and RMSE suggested that the cubist model predicted total MCPD content with the highest accuracy, followed by the RF, avNNET, nnet and PLSR models. The overfitting tendency was assessed based on differences in R2 and RMSE in the training and testing calibrations. The observations showed that the cubist and avNNET models possessed a certain degree of overfitting. However, the accuracy of these models in predicting the total MCPD content was high. Results of the consensus model showed that it slightly improved the accuracy of prediction as well as significantly reduced its uncertainty. The important variables derived from the cubist and RF models suggested that the wavenumbers corresponding to the MCPDs originated from the –CH=CH2 or CH=CH (990–900 cm−1) and C-Cl stretch (800–700 cm−1) regions of the FTIR spectrum data. In short, chemometrics in combination with FTIR analysis especially for the consensus model represent a potential and flexible technique for estimating the total MCPD content of refined vegetable oils.

Fourier transform infrared spectroscopy (FT-IR) was studied as an alternative technique for the estimation of the 3-monochloropropane-1,2-diol (3-MCPD) ester level in palm olein. The samples were the frying oils of potato chips with the addition of a synthetic or natural antioxidant. The same samples were evaluated by both the conventional method (GC-MS) and FTIR. Principal component analysis (PCA) was used to group the frying oils according to the level of the 3-MCPD esters. The results obtained by FTIR were consistent with the findings using an indirect determination method by GC-MS. Chemometric analysis was applied to correlate the content of 3-MCPD esters with the FTIR spectrum data. A partial least squares (PLS) model was able to predict the concentrations of 3-MCPD esters at the 95% confidence level with R2 values higher than 0.90.

The effects of selected antioxidants on the changes of the quality properties and 3-monochloropropane-1,2-diol (3-MCPD) esters and glycidyl ester (GE) contents in refined, bleached, and deodorized (RBD) palm olein during the deep-fat frying (at 180 °C) of potato chips were studied. The frying duration was 100 min in five antioxidant systems for three consecutive days. The antioxidants used were butylated hydroxyanisole (BHA), butylated hydroxytoluene (BHT), tert-butylhydroquinone (TBHQ), oleoresin rosemary and sage extract. Both the frying oil and the oil extracted from the fried potato chips were analyzed for the 3-MCPD esters and GE content, acylglycerol composition, free fatty acid (FFA) content, p-anisidine value (p-AV), and specific extinction coefficient K232 and K268. Generally, TBHQ and oleoresin rosemary showed significantly lower levels of 3-MCPD esters and GE. The order of effectiveness of the selected antioxidants in the frying oil and fried potato chips was BHT

3-Monochloropropane-1,2-diol (3-MCPD) esters and glycidyl esters (GE) are heat-induced contaminants which form during oil refining process, particularly at the high temperature deodorization stage. It is worth to investigate the content of 3-MCPD and GE in fries which also involved high temperature. The content of 3-MCPD esters and GE were monitored in fries. The factors that been chosen were temperature and duration of frying, and different concentration of salt (NaCl). The results in our study showed that the effect was in the order of concentration of sodium chloride

Shortening derived from palm oil is widely used in baking applications. However, palm oil and the related products are reported to contain high levels of monochloropropandiol (MCPD) ester and glycidyl ester (GE). MCPD and glycidol are known as process contaminants, which are carcinogenic and genotoxic compounds, respectively. The objective was to evaluate the effects of antioxidant addition in palm olein and stearin to the content of MCPD esters and GE in baked cake. Butylated hydroxyanisole (BHA), rosemary extract and tocopherol were used to fortify the samples at 200 mg/kg and in combinations (400, 600 and 800 mg/kg rosemary or tocopherol combined with 200 mg/kg BHA). The MCPD esters and GE content, radical formation and the quality of the fats portion were analyzed. The results showed that palm olein fortified with rosemary extract yielded less 2-MCPD ester. The GE content was lower when soft stearin was fortified with rosemary. ESR spectrometry measurements showed that the antioxidants were effective to reduce radical formation. The synergistic effects of combining antioxidants controlled the contaminants formation. In conclusion, oxidation stability was comparable either in the single or combined antioxidants. Tocopherol in combination with BHA was more effective in controlling the MCPD esters and GE formation.

Glycidyl ester (GE) is a process contaminant formed during the palm oil refining process. In this study, 156 spectra of palm-based cooking oilwere recorded by Fourier transform infrared (FTIR) spectroscopy and resulting data were processed using chemometrics approach. The relationship between spectrum data and measured data of GE content was established using Cubist, Random Forest (RF), average neural network (avNNET), and artificial neural network (nnet) model. Then, a consensus regression model was established using a fusion of those four models. GE contents measured by gas chromatography-mass spectrometer (GC-MS) were between 1.338 and 18.362 mg/kg with mean value of 6.880 ± 3.767 mg/kg and median value of 6.480 mg/kg. In this study, FTIR spectrum served as data input and calibrated using measurements from GC-MS. NMR was then applied to verify the present and structural information of GE. Prediction results of GE using the consensus model showed -high coefficient of determination (R2) value of 0.79. The contribution (in percentage) of each member model from highest to the lowest was in order Cubist > RF > avNNET > nnet. Further confirmation of the presence of GE in samples were performed using 1H NMR spectroscopy. Comprehensive analyses based on FTIR chemometrics and 1H NMR spectroscopy successfully determined GE in palm-based cooking oil.

Hand-pressed strawberry juice samples were subjected to sonication treatments (0, 15 and 30min at 20°C, 25kHz frequency). Physicochemical properties (°Brix, pH, water activity, viscosity, titratable acidity, cloud assessment and turbidity), antioxidant compounds and activity (total phenolics, ascorbic acid, anthocyanins, free radical scavenging activity), polyphenoloxidase enzyme activity, browning degree and microbial load were evaluated. Results showed non-significant changes for °Brix, pH, water activity, titratable acidity and colour parameters in sonicated samples compared to control (0min). Sonication treatments resulted in reduced viscosity and increased cloudiness and turbidity. Overall, treatment for 30min showed significant enhancement in bioactive compounds under study. Besides, sonication treatment imparted non-significant changes in polyphenoloxidase activity and in browning degree. However, sonication was incompetent in reducing microbial load. Results generated from this study were encouraging and this is expected to provide platform for future commercial applications on a pilot scale.

Soy sauce fermentation was simulated in a laboratory and subjected to 10min of sonication. A full factorial design, including different cycles, probe size, and amplitude was used. The composition of 17 free-amino acids (FAAs) was determined by the AccQ-Tag method with fluorescent detection. Main effect plots showed total FAAs extraction was favoured under continuous sonication at 100% amplitude using a 14mm diameter transducer probe, reaching 1214.2±64.3mg/100ml of total FAAs. Moreover, after 7days of fermentation, sonication treatment caused significantly higher levels (p