In order to invent a porcine gelatine detection device using microbial resources, bacterial enzymes with a preference towards porcine gelatine and their candidate genes were evaluated. Five (n = 5) bacterial strains isolated from hot spring water and wet clay, Malaysia were screened for their gelatinase activity. The gelatinase enzyme was extracted and purified using ammonium sulphate precipitation prior to performing gelatinase assay on porcine, bovine and fish gelatine medium substrates. The G2 strain or Enterobacter aerogenes (Strain EA1) was selected for whole genome sequenced after showing a consistent trend of preference towards porcine gelatine. The gelatinase candidate gene gelEA1_9 was cloned and expressed. Based on one-way analysis of variance (ANOVA) with POST-HOC Duncan test (α = 0.05), the final product of gelEA1_9 was identified as a novel gelatinase. This gelatinase presented no significant difference in activity towards porcine gelatine. Hence, the present study demonstrated an enzyme-substrate interaction for porcine gelatine identification.
The effect of 0.1-0.7% (w/w) of polyglycerol esters (PGEmix-8) on palm oil crystallization was studied using focused beam reflectance measurement (FBRM) to analyze the in-line changes of crystal size distribution during the crystallization. FBRM results show that 0.1-0.5% (w/w) of PGEmix-8 did not significantly affect nucleation but slightly retarded crystal growth. The use of 0.7% (w/w) additive showed greater heterogeneous nucleation compared to those with lower dosages of additive. Crystal growth was also greatly reduced when using 0.7% (w/w) dosage. The morphological study indicated that the palm oil crystals were smaller and more even in size than when more additive was added. Isothermal crystallization studies using differential scanning calorimetry (DSC) showed increased inhibitory effects on palm oil crystal growth with increasing concentration of PGEmix-8. These results imply that PGEmix-8 is a nucleation enhancing and crystal growth retarding additive in palm oil crystallization at 0.7% (w/w) dosage.
Fat, alkaloid and polyphenol contents of two clones of cocoa (UIT1 and PBC 140) were removed and the remaining powder was autolyzed at pH 3.5 and 5.2. Based on the results, autolysates of UIT produced at pH 3.5 exhibited the highest ability to inhibit α-amylase activity. However, no α-glucosidase inhibition activity was observed under the conditions specified. Autolysates produced under pH 3.5 caused the highest amount of insulin secretion. In streptozotocin-diabetic rats, all cocoa autolysates significantly decreased blood glucose at 4h. To assure that the results from the assays were not due to the polyphenols of cocoa autolysates qualitative and quantitative tests were applied. According to their results cocoa autolysates were found to be free from polyphenols. Analysis of amino acid composition revealed that cocoa autolysates were abundant in hydrophobic amino acids. It can be suggested that besides other compounds of cocoa, its peptides and amino acids could contribute to its health benefits.
The purpose of this study was to identify porcine-specific peptide markers from thermally processed meat that could differentiate pork from beef, chevon and chicken meat. In the initial stage, markers from tryptic digested protein of chilled, boiled and autoclaved pork were identified using LC-QTOF-MS. An MRM method was then established for verification. A thorough investigation of LC-QTOF-MS data showed that only seven porcine-specific peptides were consistently detected. Among these peptides, two were derived from lactate dehydrogenase, one from creatine kinase, and four from serum albumin protein. However, MRM could only detect four peptides (EVTEFAK, LVVITAGAR, FVIER and TVLGNFAAFVQK) that were consistently present in pork samples. In conclusion, meat species determination through a tandem mass spectrometry platform shows high potential in providing scientifically valid and reliable results even at peptide level. Besides, the specificity and selectivity offered by the proteomics approach also provide a robust platform for Halal authentication.
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.
The presence of carcinogens in food is a major food safety concern. A nanocomposite-based electrochemical DNA biosensor was constructed for potential carcinogen detection in food samples by immobilizing amine terminated single stranded DNA onto silica nanospheres deposited onto a screen-printed electrode modified using gold nanoparticles. The effect of three different DNA sequences: 15-base guanine, 24-base guanine and 24-base adenine-thymine rich DNA on carcinogen (formaldehyde and acrylamide) detection was evaluated. The competitive binding of the DNA with the carcinogen and electroactive indicator, Methylene blue (MB) was measured using differential pulse voltammetry. Optimization studies were conducted for MB concentration and accumulation time, DNA concentration, buffer concentration, pH and ionic strength. Overall, the 24-base guanine rich DNA yielded the best results with a detection limit of 0.0001 ppm, linear range between 0.0001 ppm and 0.1 ppm and reproducibility below 5% R.S.D. Finally, the results obtained using the biosensor were validated using Ames test.
Dispersive liquid-liquid microextraction method based on solidification of floating organic droplet (DLLME-SFO) was developed for the analysis of triazines. As model compounds four selected triazine herbicides namely, simazine, atrazine, secbumeton and cyanazine were employed to estimate the extraction efficiency. The experimental conditions were comprehensively studied for the DLLME-SFO method. Under the use of 10 μL of 1-undecanol as extraction solvent, 100 μL of acetonitrile as disperser solvent and 5% (w/v) NaCl for 3 min the results demonstrated that the repeatability (RSD%) of the optimised DLLME-SFO method ranged from 0.03% to 5.1% and the linearity in the range of 0.01-100 ppb. Low limits of detection (0.037-0.008 ppb), and good enrichment factors (195-322) were obtained. The DLLME-SFO method applied in water and sugarcane samples showed excellent relative recoveries (95.7-116.9%) with RSDs <8.6% (n=3) for all samples.
The present study aimed to investigate the effects of ultrasound-assisted extraction (UAE) condition on the yield, antioxidant activity and stability of the oil from papaya seed. The studied ultrasound variables were time, temperature, ultrasound power and solvent to sample ratio. The main goal was to optimise UAE condition providing the highest recovery of papaya seed oil with the most desirable antioxidant activity and stability. The interaction of ultrasound variables had the most and least significant effects on the antioxidant activity and stability, respectively. Ultrasound-assisted extraction provided a relatively high oil recovery (∼ 73%) from papaya seed. The strongest antioxidant activity was achieved by the extraction at the elevated temperature using low solvent to sample ratio. The optimum ultrasound extraction was set at the elevated temperature (62.5 °C) for 38.5 min at high ultrasound power (700 W) using medium solvent to sample ratio (∼ 7:1 v/w). The optimum point was practically validated.
The present study focused on the phytochemical profiling along with evaluation of in vitro antioxidant, α-glucosidase and α-amylase inhibitory activities of various crudes and fractions obtained from Lepisanthes fruticosa (Roxb) Leenh fruit. Ethanolic seed crude extract exhibited the strongest radical scavenging, β-carotene bleaching activity, α-glucosidase inhibition and the highest total phenolic content (TPC). Column chromatography afforded various fractions with fraction M4 being the most potent due to the strongest radical scavenging, β-carotene bleaching, α-glucosidase inhibition and greatest amount of TPC. Liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis of ethanolic seed crude extract and fraction M4 showed the presence of various phytochemicals with antioxidant and antidiabetic properties, which include mostly flavonoids and tannins. The results may suggest that the ethanolic crude seed extract and its fraction could be an excellent source of bioactive phytochemicals with antioxidant and antidiabetic potential.
Palm-based diacylglycerol (P-DAG) oils were produced through enzymatic glycerolysis of palm kernel oil (PKO), palm oil (PO), palm olein (POL), palm mid fraction (PMF) and palm stearin (PS). High purity DAG (83-90%, w/w) was obtained and compared to palm-based oils (P-oil) had significantly (P<0.05) different fatty acid composition (FAC), iodine value (IV) and slip melting point (SMP). Solid fat content (SFC) profiles of P-DAG oils as compared to P-oils had less steep curves with lower SFC at low temperature range (5-10°C) and the higher complete melting temperatures. Also, P-DAG oils in contrast with P-oils showed endothermic as well as exothermic peaks with higher transition temperatures and significantly (P<0.05) higher crystallisation onsets, heats of fusion, and heats of crystallisation. Crystal forms for P-DAG oils were mostly in the β form.
Fragaria chiloensis fruit has a short postharvest life mainly due to its rapid softening. In order to improve its postharvest life, preharvest applications of methyl jasmonate (MeJA) and chitosan were evaluated during postharvest storage at room temperature. The quality and chemical parameters, and protection against decay were evaluated at 0, 24, 48 and 72 h of storage from fruits of two subsequent picks (termed as first harvest and second harvest). In general, fruits treated with MeJA and chitosan maintained higher levels of fruit firmness, anthocyanin, and showed significant delays in decay incidence compared to control fruit. MeJA-treated fruits exhibited a greater lignin content and SSC/TA ratio, and delayed decay incidences. Instead, chitosan-treated fruits presented higher antioxidant capacity and total phenol content. In short, both the elicitors were able to increase the shelf life of fruits as evidenced by the increased levels of lignin and anthocyanin, especially of the second harvest.
The main goal of the present work was to assess the mechanism of crystallisation, more precisely the dominant component responsible for primary crystal formations and fat agglomerations. Therefore, DSC results exhibited significant effect on temperature transition; peak sharpness and enthalpy at palm stearin (PS) levels more than 40wt.%. HPLC data demonstrated slight reduction in the content of POO/OPO at PS levels less than 40wt.%, while the excessive addition of PS more than 40wt.% increased significantly PPO/POP content. The pNMR results showed significant drop in SFC for blends containing PS less than 40wt.%, resulting in low SFC less than 15% at body temperature (37°C). Moreover, the values of viscosity (η) and shear stress (τ) at PS levels over 40wt.% expressed excellent internal friction of the admixtures. All the data reported indicate that PPO/POP was the major component of primary nucleus developed. In part, the levels of PS should be less than 40wt.%, if these blends are designed to be used for margarine production.
Currently, the authentication of virgin coconut oil (VCO) has become very important due to the possible adulteration of VCO with cheaper plant oils such as corn (CO) and sunflower (SFO) oils. Methods involving Fourier transform mid infrared (FT-MIR) spectroscopy combined with chemometrics techniques (partial least square (PLS) and discriminant analysis (DA)) were developed for quantification and classification of CO and SFO in VCO. MIR spectra of oil samples were recorded at frequency regions of 4000-650cm-1 on horizontal attenuated total reflectance (HATR) attachment of FTIR. DA can successfully classify VCO and that adulterated with CO and SFO using 10 principal components. Furthermore, PLS model correlates the actual and FTIR estimated values of oil adulterants (CO and SFO) with coefficient of determination (R2) of 0.999.
This study aimed to reveal the effect of different basic emulsion structures (W/O/W and O/W) and polysaccharide additions on protein-polysaccharide composite-based emulsion gels utilizing soybean protein isolate, palm oil and konjac glucomannan. The results of texture profile, rheological tests, microstructure observations, and oral tribology showed that basic emulsion structures and konjac glucomannan addition had significant effect on the emulsion gels' properties, while the impact of konjac glucomannan addition was stronger. W/O/W double emulsion gels (DEG) exhibited lower oral friction coefficients and obtained higher scores for oiliness and juiciness during the sensory evaluation. However, O/W single emulsion gels (SEG) displayed a firmer texture and higher chewiness, a 29.62% and 49.57% increase compared to the DEG at 7% konjac glucomannan addition on the hardness and chewiness respectively. It has demonstrated the emulsion gels' potential as cube fat mimetics and feasibility of adjusting their properties by changing the basic emulsion structure.
In Malaysia, fresh ulam raja leaves (Cosmos caudatus) are eaten raw with rice. In this study, beef patties incorporated with extracts of ulam raja (UREX) and commercial green tea extract (GTE) added individually at 200 and 500 mg/kg were stored at -18°C for up to 10 weeks. Lipid oxidation, cooking yield, physicochemical properties, textural properties, proximate composition and sensory characteristics of the beef patties were compared between those incorporated with UREX, GTE and the control (pure beef patty). Incorporation of UREX or GTE at 500 mg/kg into beef patties reduced the extent of lipid oxidation significantly (P<0.05). UREX showed a strong lipid oxidation inhibitory effect, comparable with GTE. In addition, a significant improvement (P<0.05) in cooking yield and textural properties was also recorded. However, incorporation of UREX and GTE into beef patties showed no significant influence (P>0.05) on the colour, pH, proximate composition and overall sensory acceptability of the patties.
The relative oxidative stability of freshly prepared and stored liposomal and nanoliposomal systems of docosahexaenoic acid (DHA, 22:6 n-3) and eicosapentaenoic acid (EPA, 20:5 n-3) were investigated. The effects of organic solvents on the oxidative stability of liposomal polyunsaturated fatty acids (PUFAs) produced by two methods, the Bangham thin-film hydration (conventional rotary evaporation method and using organic solvents) and Mozafari (direct hydration and without using organic solvents) methods, were compared. The highest physicochemical stability was observed in PUFA liposomes prepared by the Mozafari method, followed by conventional liposomes and bulk PUFAs. There was no significant change in physicochemical stability during 10 months of cold storage (4°C) in the dark. Moreover, the comparison between liposomes (>200 nm) and nanoliposomes (50-200 nm) revealed that the surface charge, physical stability and oxidative stability of liposomal PUFAs increased as the size of the liposomes decreased. The differences in the oxidative stability of PUFAs may be due to the protective effects of aqueous systems, which indicate the advantage of using non-organic solvent (water and CO(2)) techniques in liposome manufacturing.
The aim of the present research was to evaluate the application, stability and suitability of ω3 polyunsaturated fatty acids (PUFAs) incorporated nanoliposomes in food enrichment. Nanoliposomal ω3 PUFAs was prepared by Mozafari method, and their application in bread and milk was compared with unencapsulated (fish oil) and microencapsulated ω3 PUFAs. Sensory evaluation was conducted to determine the perceptible sensory difference/similarity between control, unencapsulated, microencapsulated, and nanoliposomal ω3 PUFAs enriched foods. Results showed no significant (p=0.11) detectable difference between control and nanoliposomal ω3 PUFAs enriched samples while, samples enriched with unencapsulated or microencapsulated ω3 PUFAs showed significant (p=0.02) fishy flavor. Moreover, significantly (p<0.01) higher ω3 PUFAs % recovery and lower peroxide and anisidine values were observed in nanoliposomal ω3 PUFAs enriched samples in comparison with other samples. In conclusion, an effective and reproducible method for application of ω3 PUFAs in the food system was developed.
Graphene (G) modified with magnetite (Fe3O4) and sol-gel hybrid tetraethoxysilane-methyltrimethoxysilane (TEOS-MTMOS) was used as a clean-up adsorbent in magnetic solid phase extraction (MSPE) for direct determination of acrylamide in various food samples prior to gas chromatography-mass spectrometry analysis. Good linearity (R2=0.9990) was achieved for all samples using matrix-matched calibration. The limit of detection (LOD=3×SD/m) obtained was 0.061-2.89µgkg-1 for the studied food samples. Native acrylamide was found to be highest in fried potato with bright-fleshed (900.81µgkg-1) and lowest in toasted bread (5.02µgkg-1). High acrylamide relative recovery (RR=82.7-105.2%) of acrylamide was obtained for spiked (5 and 50µgkg-1) food samples. The Fe3O4@G-TEOS-MTMOS is reusable up to 7 times as a clean-up adsorbent with good recovery (>85%). The presence of native acrylamide was confirmed by mass analysis at m/z=71 ([C3H5NO]+) and m/z=55 ([C3H3O]+).
Cysteine proteases in pineapple (Ananas comosus) plants are phytotherapeutical agents that demonstrate anti-edematous, anti-inflammatory, anti-thrombotic and fibrinolytic activities. Bromelain has been identified as an active component and as a major protease of A. comosus. Bromelain has gained wide acceptance and compliance as a phytotherapeutical drug. The proteolytic fraction of pineapple stem is termed stem bromelain, while the one presents in the fruit is known as fruit bromelain. The amino acid sequence and domain analysis of the fruit and stem bromelains demonstrated several differences and similarities of these cysteine protease family members. In addition, analysis of the modelled fruit (BAA21848) and stem (CAA08861) bromelains revealed the presence of unique properties of the predicted structures. Sequence analysis and structural prediction of stem and fruit bromelains of A. comosus along with the comparison of both structures provides a new insight on their distinct properties for industrial application.
Formaldehyde is added illegally to food to extend its shelf life due to its antiseptic and preservation properties. Several research has been conducted to examine the consequences of adulteration with formaldehyde in food items. These findings suggest that adding formaldehyde to food is considered harmful as it accumulates in the body with long-term consumption. In this review includes study findings on food adulteration with formaldehyde and their assessment of food safety based on the analytical method applied to various geographical regions, food matrix types, and their sources in food items. Additionally, this review sought to assess the risk of formaldehyde-tainted food and the understanding of its development in food and its impacts on food safety in light of the widespread formaldehyde adulteration. Finally, the study would be useful as a manual for implementing adequate and successful risk assessment to increase food safety.