Muhammad Asim Shabbir

Effect of Thermal Treatment on Meat Proteins with Special Reference to Heterocyclic Aromatic Amines (HAAs)

Meat is one of the most imperative protein sources available with respect to its production and consumption. It is the richest source of some valuable nutrients like proteins, essential amino acids, polyunsaturated fatty acids, vitamins, and minerals like iron, zinc, and selenium. Thermal treatment produces conformational changes in protein structure as well as flavor, texture, and appearance, and chemical properties of the ingredients are also changed. Heterocyclic aromatic amines (HAAs), potent mutagens/carcinogens, are formed during the cooking of meat at high temperature. The review paper highlights the effects of various cooking methods, i.e., pan-frying, deep-frying, charcoal grilling, and roasting, on the formation of HAAs. The levels of HAAs produced in cooked meats vary depending upon the cooking method, time of cooking, and the type of meat being cooked. Metabolic behavior of HAAs is very unique, they interfere in the activity of many enzymes, modify the metabolic pathways, and lead to the adduct formation of DNA. The application of black pepper and several other spices during processing may reduce the formation of these (HAAs) mutagenic compounds.

Complete Genome Sequence of a Velogenic Neurotropic Avian Paramyxovirus 1 Isolated from Peacocks (Pavo cristatus) in a Wildlife Park in Pakistan

ABSTRACT Avian paramyxovirus serotype 1 (APMV-1) was isolated from an acute and highly contagious outbreak in peacocks (Pavo cristatus) in a wildlife park in Pakistan. A velogenic neurotropic form of APMV-1 caused a 100% case fatality rate and killed 190 peacocks within a week. Biological and serological characterizations showed features of a velogenic strain of APMV-1, and these results were further confirmed by sequence analysis of the cleavage site in the fusion protein. The complete genome of one of the isolates was sequenced, and phylogenetic analysis was conducted. The analysis showed that this isolate belonged to genotype VII, specifically, to subgenotype VIIa, and clustered closely with isolates characterized from Indonesia in the 1990s. Interestingly, the isolate showed significant differences from previously characterized APMV-1 isolates from commercial and rural chickens in Pakistan. The work presented here is the first complete genome sequence of any APMV-1 isolate from wild birds in the region and therefore highlights the need for increased awareness and surveillance in such bird species.

Organogelators as a Saturated Fat Replacer for Structuring Edible Oils

Fats are among the most vital macronutrients that are needed to keep your body healthy. While eating moderate amounts is beneficial, excessive intake of fats can cause serious complications such as cancer and other cardiovascular diseases. These problems can be reduced by substituting the saturated and trans fats with mono- and poly-unsaturated fats. Unfortunately, these substitutions do not provide the desired texture and other physical properties in the final product. So to solve this issue, the concept of “organogels” was introduced. Structuring of edible oil is becoming a potential strategy to reduce/eliminate the trans/saturated fats. Researchers are working to introduce fat like properties in these liquid oils by different strategies like imparting some compounds in oil which leads to its gelation. This review provides a detailed study on the organogel’s building blocks, its structuring techniques, organogelator’s effects, problems associated with the development of organogels, and their solutions. Applications of organogels in different fields of life and particularly in the food industry are also discussed. Efforts are required to develop analytical methods for understanding the underlying mechanisms of structuring organogels and to explore more food grade organogelators.

Impact of Dietary α-Lipoic Acid on Antioxidant Potential of Broiler Thigh Meat

The lipid oxidation depressed the meat quality and can be triggered during industrial processing. The current study was designed to assess the antioxidant activity of thigh meat and meat products enriched with natural antioxidants (α-lipoic acid and α-tocopherol acetate). Broilers (21 days) were fed on feed supplemented with varying α-lipoic acid and constant concentration of α-tocopherol acetate for 3 weeks. Birds were slaughtered at the age of 42 days and meat samples were collected and stored for further analysis and product preparation. TPC and DPPH value indicated that meat of broilers receiving 100 mg of α-lipoic acid with 200 mg of α-tocopherol acetate/kg of feed possessed the highest antioxidant activity. TBARS and peroxides values were found to be lower for meat of broilers fed on different levels of α-lipoic acid. The antioxidants (lipoic acid and tocopherol) enrichment in meat helps to reduce PUFAs. A similar lipid stability trend was observed in nuggets prepared from broiler thigh meat and maximum sensory evaluation scores for nuggets prepared from thigh meat of broilers having the highest dose of lipoic acid. The lipoic acid supplementation in feed enhances the antioxidant capacity of thigh meat and meat products.

Immunochemical characteristics of wheat proteins

Abstract The purpose of this paper is to provide a comprehensive overview of wheat protein characteristics and of enzyme-linked immunosorbent assay (ELISA) technique for wheat quality characteristics determination. Literature review is to report the identification of low and high molecular weight subunits of glutenins with ELISA. Immunological assay has been reported to be used as an alternative method to reduce the test time and cost. ELISA is an immunological technique involving an enzyme (a protein that catalyses a biochemical reaction) to detect the presence of an antibody or an antigen in a test sample. Currently available knowledge on immunochemical characteristics of wheat proteins is insufficient. Thats why this review is unique in its comprehensive nature for immunochemical characteristics of wheat proteins.

Application of enzyme-linked immunosorbent assay for the assessment of spring wheat quality

The present project was undertaken with the key objective to find out relationship of HMW and LMW glutenin sub-units and immunological test with bread making quality. The antibody response assessed through animal modelling by using rabbits as test animals showed significant variation towards high molecular weight glutenin (HMG) and low molecular weight glutenin (LMG) of different spring wheat varieties. A significant and positive relationship of bread sensory attributes with antibody response against HMG was observed. The mastication (r=0.64), texture (r=0.69), taste (r=0.72), aroma (r=0.68), grain (r=0.71) and total score (r=0.83) showed highly significant association with antibody response against HMG. The loaf volume correlated linearly with that of HMW antibody response (r=0.51). The LMG antibody response was negatively correlated with flour characteristics and sensorial attributes with non significant level.

Electrophoretic and Functional Mapping of Indica Rice Glutelin Protein Isolates

Rice glutelin protein isolates were extracted from export quality Pakistani rice varieties and their milling fractions, characterized by dry matter yield, protein content, molecular weight profile using sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) and also explored the functional properties. The glutelin protein content and its dry matter yield varied significantly among rice varieties and their milling fractions. The highest dry matter yield and protein content was found in brown rice of Basmati 2000 rice variety and the lowest dry matter yield and protein content was observed in white rice of KS-282. The electrophoretic pattern showed 11 different molecular weight subunits with three major polypeptides observed at 32.1 to 34.0, 23.9 to 24.5, and 12.1 to 16.1 kDa, respectively. The overall electrophoretic profile and alpha glutelin subunits in different rice samples ranged from 12.1 to 100.9 and 32.1 to 34.0 kDa, respectively, while beta glutelin subunits ranged from 23.9 to 24.5 kDa. The variation in rice milling fractions did not show any effect on the molecular weight subunit composition of glutelin within a variety. Little is known about its functional properties, which have been shown to be variety specific. Thus, it is of importance to examine glutelin isolates from Pakistani rice varieties. The functional properties of glutelin isolates showed a non-significant effect on foaming capacity and stability within varieties, and overall it had poor foaming properties but it had good gelling properties, which may be a very promising characteristic for its use in different food applications.

Immunological appraisal of modified gluten to trim down celiac toxicity

The aim of the present research was to modify wheat gluten by binding methionine to gluten proteins to develop bread for celiac disease (CD) patients. The highest protein content, wet gluten content, dry gluten content and sodium dodecyl sulphate-sedimentation value were shown by the wheat variety AARI-11, therefore, it was selected for gluten modification. The bound methionine to gluten proteins was found increasing along the reaction time as the reaction proceeds and at a maximum near to 60 minutes and then it starts decreasing. The lowest immunoreactivity of the modified gluten was obtained near to 60 min of reaction at pH 10. The results for immunoglobulin A (IgA) index showed that the serum of each patient had positive IgA index to gliadins from unmodified gluten, but just sera of two patients had positive IgA index to gliadins from modified gluten and when these proteins were digested, the sera of no patients serum had positive IgA reactivity. Among physical characteristics of breads 2 hours after baking, the specific volume of the modified gluten containing bread (4.13 ± 0.14 cm3/g) was lower than the control bread (4.59 ± 0.21 cm3/g). However, bread made with modified gluten had higher specific volumes than other gluten-free breads. Texture of the modified gluten was also affected by modification. Finally, the gluten content in the modified gluten bread was 79 ppm which is under the limits set by the Codex Alimentarius for food with reduced gluten content should have from 20 to 100 ppm. The study concludes that the incorporation of steric immensity into gluten proteins in order to shun immune recognition is the most promising approach to acquire wheat-based products that are tolerated by CD patients.

Preventing oxidation of canola and sunflower oils by addition of pomegranate seed oil

The study was designed to explore the antioxidative effect of pomegranate seed oil (PSO) at different concentrations (5 and 7%) against oxidation of plant-based oils (canola oil and sunflower oil) during storage (60 days) as compared to artificial antioxidant butylated hydroxyanisole (BHA, 200 ppm). Rancimat and Schaal oven analysis were employed for the assessment of potential consequences of PSO against oxidation in plant based oils. The variation in total phenolic contents (TPC), antioxidant activity, peroxide value (POV), and tocopherol contents during storage were evaluated by Schaal oven test at 62 °C. The substantially (P≤0.05) higher induction period (IP) values were observed for PSO blended oil samples as compared to blank oil samples. The addition of PSO in plant-based oils improved the oxidative stability by enhancing the antioxidant potential and TPC, decreasing POV, and slowing down the degradation of tocopherol contents during storage. The findings of the present study suggest that PSO might be used as an alternative potential antioxidant to synthetic antioxidants.

Immunological appraisal of wheat varieties in relation to chapatti-making characteristics

The current research work was conducted to characterize wheat proteins through immunochemical techniques and to find out their relationship with wheat quality traits. The results revealed that wheat variety AARI-11 possessed higher protein content (11.96%), wet gluten (31.39%), dry gluten (9.66%), Pelshenke value (190.52 min), and SDS-Sedimentation value (28.27 ml) than other tested varieties. The chapattis prepared from the wheat variety AARI-11 got significantly higher sensory scores owing to its higher protein contents. The wheat variety AARI-11 also exhibited significantly the highest antibody response against all the assessed protein fractions. The results of the present study suggest that anti-glutenin and anti-high molecular weight glutenin subunits (HMW-GS) antibody response was found positively correlated to the quality characteristics of flours and chapattis. The present study suggests that the use of antibodies response against glutenin and HMW-GS offers good tool for predicting quality and suitability of wheat to chapatti-making quality.