Tariq Masud

Nutritional and Health Perspectives of Beans (Phaseolus vulgaris L.): An Overview

Beans, the variants of Phaseolus vulagris, are nutritionally and economically important food crop in each part of the world. Besides providing nutrients such as multifaceted carbohydrates, elevated proteins, dietary fiber, minerals, and vitamins, these also contain rich variety of polyphenolic compounds with prospective health benefits. This review mainly focuses the important nutritional aspects of beans as well as their contribution in decreasing the risks of chronically degenerative diseases.

Lactobacillus acidophilus: Characterization of the Species and Application in Food Production

L. acidophilus is a homofermentative, microaerophilic, short chain gram positive microorganism with rod morphology having its bacteriocins belonging to class II a. Several bacteriocins of L. acidophilus have been isolated and characterized. These are structurally similar, but their molecular weight varies as well as their spectrum of antimicrobial activity. They exhibit important technical properties, i.e., thermostability and retaining of activity at a wide pH range along with strong inhibitory actions against food spoilage and pathogenic bacteria make them an important class of biopreservatives. L. acidophilus can be added as an adjunct in many food fermentation processes contributing to unique taste, flavor, and texture. It also preserves the products by producing lactic acid and bacteriocins. A lot of new information regarding the bacteriocins of L. acidophilus has emerged during the last few years. In this review, an attempt has been made to summarize and discuss all the available information regarding the sources of bacteriocins production, their characteristics, and their antimicrobial action along with their application.

Mechanisms Involved in the Therapeutic Effects of Soybean (Glycine Max)

Soybeans contain nutritional and medicinal properties. It is a rich source of quality proteins, phytosterols, fibers, and other biologically active compounds, notably daidzein and genistein. Soybeans provide health benefits due to their functional ingredients such as proteins, polysaccharides, and isoflavones. These functional ingredients play a vital role in the reduction of different types of cancer, cardiovascular diseases, postmenopausal problems, diabetes, and some neurodegenerative disorders. This review primarily envisages the different mechanisms involved in the therapeutic effects of soybean components as well as their contribution toward the reduction of different diseases.

Preliminary characterisation of bacteriocin produced byLactobacillus acidophilus TS1 isolated from traditional dahi

Antimicrobial activity of 79 strains ofLactobacillus isolated from indigenous dahi were tested against the indicator strains of food pathogens (Escherichia coli, Streptococcus faecalis, Staphylococcus aureus, Salmonella typhi). Among these only eleven isolates produced inhibition zones of variable size against indicator microorganisms. Later on, only one strain ofLactobacillus acidophilus (TS1) was found to produce a wider zone of inhibition against all indicator microorganisms. The antimicrobial activity of this strain was inactivated by the proteolytic enzyme proteinase K and trypsin but not by α-amylase and lipase thus confirming its proteinaceous nature. It also showed a wide range of thermostability from 70–121°C for 15 min and retained their antimicrobial activity over a wide range of pH (3–10). The addition of bacteriocin to the earlier growth phase showed pronounced inhibition againstE. coli, andStreptococcus faecalis, as compared toStaphylococcus aureus, andSalmonella typhi. The molecular weight of the substance was in the range of 7.5 kDa. This result suggested that bacteriocin might be useful as a biopreservative in different food commodities.

Physico-chemical, functional and processing attributes of some potato varieties grown in Pakistan

A study was generated from six commercial potato varieties and studied for their physical, chemical, functional and processing attributes. Lady Rosetta followed by Hermes was the most appreciable varieties concerning their physical attributes. A positive correlation (R = 0.765) existed between tuber firmness and specific gravity. Lady Rosetta and Atlantic attained maximum dry matter and starch contents. Agria contained lesser amount of sugar and Desi contained maximum fat and fiber contents. Highly significant correlation was estimated between dry matter and starch contents (R = 0.967). Hermes and Agria were preferred over all other varieties for their mineral contents, but its functional attributes were found maximum in Desi followed by Hermes. A promising correlation was reported between most of these functional parameters with distinctive correlation between total phenolic contents and radical scavenging activity (R = 0.903). Post processing parameters in Lady Rosetta indicated its preference over all other varieties followed by Hermes and Atlantic. Key words : Potato varieties, physico-chemical, functional attributes, processing.

Selection and characterization of probiotic culture of Streptococcus thermophilus from dahi

For the isolation of probiotic cultures of Streptococcus thermophilus from dahi, we collected 120 samples from the southern regions of Punjab, Pakistan. Eleven isolates were obtained, and six were scrutinized for antibacterial activities against food-borne pathogens. The carbohydrate fermentation profile of these six strains was determined by the API50 CHL system. Additionally, these strains were amplified for their 16S rRNA regions to confirm their genotypic relationship. Furthermore, phenotypic characteristics among these strains were established by S-layer protein analysis of their cell walls by sodium dodecyl sulphate-polyacrylamide gel electrophoresis and by plasmid profiling. The outer cell wall layers of these strains have 6–14 different sizes of protein bands of 27, 34, 37, 40, 45 and 60 kDa molecular weight. Similarly, except S02FT, all strains have a single prominent plasmid of 23 kbp, whereas S02FT has an additional plasmid of 9 kbp. On the basis of this unique feature and a wide spectrum of killing patterns against pathogenic bacteria, S. thermophilus S02FT was further characterized. This culture showed an optimum antibacterial activity of 800 AU/ml at pH 5.0–5.5 and a temperature of 30–37°C. It grows well in in vitro acidic conditions and tolerates bile salt up to 2% concentration. It was resistant to nalidixic acid, ciprofloxacin, gentamicin and sulphamethoxazol, but showed intermediate behaviour to vancomycin and erythromycin.

Effect of flour processing on the quality characteristics of a soy-based beverage

Four treatments (roasting, germination, autoclaving and an application of 0.5% EDTA+0.5% sodium hydroxide) were used to reduce the beany flavour of soya beans to produce a soy-based beverage. While germination significantly increased the protein level as compared to the other treatments, the maximum reduction of the beany flavour was achieved by the 0.5% EDTA+0.5% sodium hydroxide application. The soya beans that underwent this treatment were used during the second phase for optimized beverage formulation. During the second phase, a beverage was prepared according to different formulations and analysed for chemical composition and total viable count during a two-month storage period. During storage, the beverage samples exhibited variations in several parameters. The acidity, reducing sugars and total sugars increased, while the ascorbic acid, total soluble solids and pH decreased. Overall, chemical and microbial analyses showed the stability of the product during the storage period.

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.

Photo-induced changes in quality attributes of potato tubers during storage

The retail display of potato tubers is carried out in supermarkets under additional light sources to impart aesthetic value and consumer’s attention, however, is associated with potato greening and associated disorders. The objective of this study was to identify a most appropriate light source for potato variety ’Lady Rosetta‘ along with photo-induced changes in different quality parameters. Potato tubers were placed for 27 days at ambient storage (25 ± 2 °C) under different light sources i.e. blue, fluorescent, green, mercury and red along with dark storage, which also served as normal control. In general, quality parameters, such as sugars, chlorophyll, total glycoalkaloids, increase while attributes, such as starch and ascorbic acid decrease during the storage period. The initial increase followed by final decline has been observed in parameters, such as total phenolic contents and radical scavenging activity. The results showed maximum retention of different quality attributes in dark potato storage. Amongst different light sources mercury and green light retained appreciable retention of different quality parameters with non-significant difference estimated between them in most of the studied parameters. Storage of potato under fluorescent, red and blue light proved to be precarious due to skin discoloration. Overall results revealed tuber sensitivity to different colored light along with their potential storage stability in the retail markets.

Transition in quality attributes of potato under different packaging systems during storage

The suitability of different packaging materials i.e. jute, nylon, polypropylene, cotton, low density polyethylene, medium density polyethylene and high density polyethylene were studied along with the control on the premium potato variety “Lady Rosetta”. After the harvest potato tubers were washed, sorted, graded, cured and subsequently stored in different packaging materials at ambient temperature (25±2 o C). Transition in quality attributes of potato tubers under different packaging materials were studied on the basis of their physico-chemical and functional parameters. Overall results revealed that packaging materials had significant (p ≤ 0.05) effect on most of the quality attributes studied. In general weight loss, glucose, glycoalkaloids, polyphenol oxidase, peroxidase, increased while ascorbic acid contents decreased with the increase of storage time. Total phenolic contents and radical scavenging activity showed a sort of parabolic trend during the storage period. Amongst different packaging employed potato stored in polypropylene and low density polyethylene packaging presented best overall retention of vital quality attributes during 63 days storage however, tensile strength of polypropylene packaging made it advantageous for prolonged potato storage coupled with easy transit operations during marketing.