Physico-Chemical Methods for Determination of Lard in Food Products for Halal Authentication Study

Food authenticity is a great concern not only for consumers but also for food producers. Lard and pork are prohibitedto be consumed by followers of Islamic religion. Lard and pork intakes are associated with several health problems. Because of the restriction reasons to consume lard and pork and its biological implications, indeed, analytical methods offering fast and reliable methods are required. This article will describe some physico-chemical methods i.e. Fou- rier transform infrared (FTIR) spectroscopy, chromatography, electronic nose, and differential scanning calorimetry (DSC) used to analyze the presence of lard and pork in food products

Physico-chemical properties and quality of palm-based vegetable ghee

Samples of trans-free vegetable ghee were made using palm oil/palm stearin/palm olein (PO/POs/POo) blends (set A) and using palm oil/palm stearin/palm kernel olein (PO/POs/PKOo) blends (set B). Palm stearin of iodine value (IV) 30 was used in this study. The products were evaluated for their physical and chemical properties. Changes in quality during storage were monitored during a period of 16 weeks. Most of the vegetable ghee were granular (grainy) and had a shiny appearance. Chemical analyses indicated that vegetable ghee consisting of PO/POs/POo had higher IV (47.7-52.4) than the PO/POs/PKOo vegetable ghee due to their higher content of unsaturated fatty acids, 46.0-50.0% compared to 36.6-45.0% in Set B. Decreasing the amount of palm oil while increasing palm stearin in the formulations resulted in higher slip melting point (SMP) and higher yield values. Eutectic interaction was noted in PO/POs/PKOo blends. The crystals in samples PO/POs/POo (set A) were predominant in the §’ polymorphic form. One formulation in set B (B4) exhibited § crystallinity. Free fatty acids (FFA) were lowest in samples PO/POs/POo 80:5:15 (A4) and PO/POs:/PKOo 80:5:15 (B4) throughout storage. There was no clear trend on anisidine value (AV) while IV remained almost constant. Selected vegetable ghee, A4 wasused to shallow fry roti canai and for cooking nasi minyak. Sensory evaluation on these two products revealed that there was no significant difference (P < 0.05) in texture, taste and overall quality between samples A4 and B4

The impact of lipid content, cooking and reheating on volatile compounds found in narrow-barred Spanish mackerel (Scomberomorous commerson)

Effects of four cooking methods (microwave cooking, grilling, steaming and shallow fat frying) and reheating by microwave on volatile profile in S. commerson were evaluated. Thirty compounds were identified in GC-MS analysis of raw samples. The number of volatile compounds had increased to 36, 46, 45 and 45 compounds in microwave cooked, grilled, steamed and shallow fat fried samples, respectively. Total concentrations of volatile had increased from 72.80 to 111.06, 74.25, 112.19 and 92.37 μg/kg, respectively. The concentration and new flavor compounds were increased by chill-reheating, due to the fast oxidation. The concentration of alcohol and aldehydes increased significantly (P<0.05). The hexanal amount also increased in all samples and indicated a marked development of warmed-over flavor. Quantitative and qualitative (P<0.05) differences were observed in volatile compounds between raw and cooked samples

Refined oil production from patin catfish (Pangasianodon hypophthalmus) by-products

In this study, oil was extracted from the liver and visceral fat of Patin (Pangasianodon hypophthalmus) and refined. The yield of oil after refining was 49.98%. The major yield loss (34.20%) happened during the degumming procedure. Fatty acids found in the crude and refined oil were C12:0, C14:0, C14:1, C16:0, C16:1, C18:0, C18:1, C18:2, C18:3, C18:4, C20:0, C20:1, C20:4, C20:5, and C22:6. The dominant saturated, monounsaturated and polyunsaturated fatty acids were C16:0, C18:1 n-9, and C18:2 n-6, respectively. The total amounts of monounsaturated fatty acids did not change significantly during refining procedure (p>0.05), whereas the total amount of saturated and polyunsaturated fatty acids changed significantly (p<0.05). The n-3 to n-6 ratios of crude, degummed, neutralized, bleached, and deodorized oils were 1.11, 1.06, 1.05, 1.02, and 1.01, respectively

Proximate and fatty acid composition of liver and fatty tissue of patin catfish (Pangasianodon hypophthalmus)

The visceral storage fat and liver of patin catfish (Pangasianodon hypophthalmus) are normally discarded, which incurs cost and can cause environmental pollution. However, these may be potential sources to extract fish oil. The proximate and fatty acid compositions of liver and fatty tissue of patin catfish were investigated to evaluate the suitability of these by-products for extracting fish oil. Fat was extracted using a low temperature solvent extraction method. The average fat content of fatty tissue and liver of females were 77.64 and 11.71%, respectively, whereas in males this was 73.23 and 9.59%, respectively. Fatty acids found in the extracted oil of these byproducts were C12:0, C14:0, C14:1, C16:0, C16:1, C18:0, C18:1, C18:2, C18:3, C18:4, C20:0, C20:1, C20:4, C20:5, and C22:6. The major fatty acids presented in these tissues were palmitic (C16:0), oleic (C18:1 n-9), and linoleic acid (C18:2 n-6). The total amount of polyunsaturated fatty acids of liver from male and female patin catfish were 13.31 and 13.30%, respectively, whereas in the fatty tissue these were 11.64 and 12.09%, respectively. The n-3 to n-6 ratios of liver and fatty tissue of females were 1.61 and 0.95, respectively, whereas in male fish these were 1.31 and 1.05, respectively. Results of this study indicated that the liver and fatty tissues of patin catfish are suitable sources of fish oil specifically due to the presence of monounsaturated and n-3 polyunsaturated fatty acids

A new method for determination of tert-butylhydroquinone (TBHQ) in RBD palm olein with FTIR spectroscopy

Fourier transform infrared (FTIR) spectra of refined bleached and deodorized (RBD) palm olein samples between 3600 and 2800 cm-1 were used for quantitative determination of the content of tert-butylhydroquinone (TBHQ). The method was based on sodium chloride (NaCl) windows with transmission path fixed at 50 μm at room temperature. Fifty stripped oil samples spiked with known amounts of TBHQ concentrations up to 300 mg/ kg (ppm) were separated into two sets for calibration and validation models based on partial least squares (PLS) analyses. The accuracy of the method was comparable to that of the method established by the International Union of Pure and Applied Chemistry (IUPAC) with a coefficient of determination (R2) of 0.9961 and standard error of calibration of (SEC) 5.06. The model was validated, and the R2 of validation and standard error of prediction were 0.9951 and 6.49, respectively. The standard deviation of difference for repeatability for the method was comparable to that for the IUPAC method. The new FTIR method developed for determining TBHQ in palm olein was demonstrated to be efficient, accurate, rapid and required minimum solvent as only acetone was used for cleaning NaCl windows. The method is suitable for routine quality control analysis. © Copyright 2004, Blackwell Publishing

Differential scanning calorimetric analysis for determination of some animal fats as adulterants in palm olein

A study was conducted to assess the use of differential scanning calorimetry (DSC) for monitoring the presence of common animal fats such as genuine lard (GLD), chicken fat (CF) and beef tallow (BT) as adulterants in palm olein. Pure palm olein samples spiked separately with GLD, CF and BT in various levels (1 to 20%) were analyzed using DSC to obtain the cooling profiles. High performance liquid chromatographic (HPLC) analyses were also performed to obtain compositional changes in triacylglycerols (TAG) of these samples. Qualitative differences in the cooling-thermograms of adulterated samples are proposed as a basis for the identification of adulteration peaks and differentiating the unadulterated sample of palm olein from those adulterated with above mentioned animal fats. As the adulteration increased from 3% to 20%, the peaks corresponding to GLD and CF were found to appear in the low-temperature region below -42.75°C whereas that corresponding to BT adulteration appeared in the high-temperature region above 8.5°C. Despite their close proximity in position, GLD and CF adulteration peaks were shown to be distinguishable by making use of the subtractive procedures facilitated by the DSC computer software

Compositional and thermal analysis of RBD palm oil adulterated with lipase-catalyzed interesterified lard

A study was conducted to determine the presence of enzymatically randomized lard (ERLD) as adulterant in RBD palm oil using three different analytical techniques namely gas liquid chromatography (GLC), reversed phase high performance liquid chromatography (RP-HPLC) and differential scanning calorimetry (DSC). Lard extracted from the adipose tissues of pig was enzymatically interesterified using nonspecific lipase from Pseudomonas sp. Compositional and thermal characteristics of ERLD was compared with those of genuine lard (GLD). RBD palm oil samples adulterated separately with various levels of GLD and ERLD were analyzed using GLC, HPLC and DSC. Both GLC and HPLC did not show any characteristic adulteration peaks that enable RBD palm oil adulterated with either GLD or ERLD to be distinctly identified from those adulterated with chicken fat (CF), whereas DSC provided a better means of detection of lard with the detection limit of 1%

Composition and thermal analysis of lard stearin and lard olein

Lard being an edible fat could be used in different forms in food systems. In this study, composition and thermal analysis of lard stearin (LS) and lard olein (LO) were undertaken to determine some common parameters which would enable their detection in food. A sample of native lard was partitioned into LS and LO using acetone as solvent and the fractions were compared to the original sample with respect to basic physico-chemical parameters, fatty acid and triacylglycerol (TAG) composition, and thermal characteristics. Although LS and LO displayed wider variations in basic physico-chemical parameters, thermal properties and solidification behavior, they do possess some common characteristic features with regard to composition. In spite of the proportional differences in the major fatty acids, both LS and LO are found to possess extremely high amount of palmitic (C16:0) acid at the Sn-2 positions of their TAG molecules. Similar to native lard, both LS and LO contained approximately equal proportions of TAG molecules namely, linoleoyl-palmitoyl-oleoyl glycerol (LPO) and dioleoyl-palmitoyl glycerol (OPO). Hence, the calculated LPO/OPO ratio for LS and LO are comparably similar to that of native lard