Muhammad Imran Al-Haq

An apparatus for electric-field-induced protein crystallization

A new device has been fabricated for electric field-induced protein crystallization with the microbatch method. In conjunction with this, a specialized tray using inexpensive plastic film has been developed for economical set-up of the experiments. Crystallization can be conducted using AC or DC voltage.

Protein crystallization under an electric field

New methods for improving the quality of protein crystals are always being sought. Electric-field-induced protein crystallization is one of them. A few devices have already been developed. We conducted a series of experiments for several years and fabricated many electrode panels to realize a device for electric-field induced protein crystallization for the microbatch method. The review mainly deals with the application of the various devices that have so far been reported in the literature on the subject, including an overview of the work that has already been conducted. The factors affecting the electric-field-induced protein crystallization are also discussed.

Application of Electrolyzed Water in Food Processing

Food Safety has to be ensured at each processing step including handling, washing of raw materials, cleaning of utensils/pipelines, packaging, etc. Different techniques are applied to achieve this task. Use of Electrolyzed water is the product of a new concept developed in Japan and getting popularity in other countries as well. Little is known about its principle of having sterilization effect. There are different schools of thought. Some believe it is presence of chlorine species, others believe on its low pH. Few papers emphasized that it is due to its high Oxidation Reduction Potential (ORP) and some says that it the mixture of all these points. But the fact remains that it possesses high bactericidal, virucidal, and moderate fungicidal properties. Some studies have been carried out in Japan, China, and USA on application of Electrolyzed Water in the field of food processing. This is an emerging technology with a lot of potential. It is cost effective and possesses environment friendly properties. To produce it, an apparatus is required that utilizes common salt and an electric source. It can be produced at site, as the size of the machine is quite small. Studies have been done on its use as a sanitizer for fruits, utensils, and cutting boards. It can also be used as a fungicide at postharvest processing of fruits and vegetables, and as a sanitizer for washing carcasses of meat and poultry.

MEASUREMENT OF FIRMNESS OF IRWIN MANGOES BY A NON-DESTRUCTIVE ACOUSTIC TESTER DURING COLD STORAGE

Mangoes (Mangifera indica L., cv. ‘Irwin’) grown in plastic greenhouses in the Okinawa Islands, Japan, were obtained and stored at 5°C, 10°C, 15°C, and in ambient conditions (20°C to 25°C) for 21 days. Their sound velocity was recorded by an instrument named the “Firm Tester,” which uses an acoustic transmission technique to indicate firmness index as a function of transmission velocity (TV). Magnitude of TV indicates fruit firmness. As the storage period advanced, the transmission velocity decreased. It was evident that ripened mangoes could be stored at 5°C without occurrence of chilling injury (CI), but non-ripened mangoes stored at the same temperature showed signs of CI. The Firm Tester provided a true firmness index of Irwin mangoes non-destructively. Commercialization of the Firm Tester could help the growers, packers, and retailers judge the firmness of fruit non-destructively.

The possible role of organic acids as allelochemicals in Tamarindus indica L. leaves

Tamarindus indica L. is well known for its acidic nature and allelopathic potential, but to date, little is known about its organic acids playing their role as allelochemicals. Hence, in the present study, identification, quantification, and contribution of organic acids present in its leaf extract were conducted using the principle of bioassay-guided procedure. High pressure liquid chromatography identified four organic acids, viz. citric, malic, oxalic, and tartaric acids, in its leaf aqueous extract with the predominance of oxalic acid (7.5 g kg−1 leaves fresh weight) followed by tartaric acid (7.3 g kg−1). The allelopathic activity of identified acids and aqueous extract was evaluated on lettuce seedlings growth based on the specific activity (EC50). The crude extract reduced radicle growth more adversely than hypocotyl at the concentration of 2.5 g L−1 (EC50). It hindered the normal physiological growth process through weak and curly seedlings, and necrosis of their tips. Among the identified acids, oxalic acid had the highest specific activity (40 mg L−1) and citric acid had the lowest (>1000 mg L−1). As a consequence of its high contents, the total activity, a function of specific activity and concentration, of oxalic acid (188) was found higher followed by tartaric acid (146). The contribution of both acids influencing the specific activity of the crude extract was then turned out to be 74%. To the best of our knowledge, this is the first report identifying the oxalic and tartaric acids as growth inhibitors in tamarind leaves and quantifying their contribution in its allelopathic expression. Based on the total activity, the results suggested that oxalic and tartaric acids are the major allelochemicals in tamarind leaves. The allelopathic potential of these acids might promote the development of natural herbicides as an alternative to the synthetic ones in a most sustainable manner.

Uses of Non-Destructive Acoustic Firm Tester in Horticulture and Food Science

In Japan, cost of production of fruits is exorbitantly high and reduction of postharvest losses is of the prime importance. An objective, non-destructive technique is needed to field test ripeness of fruits. Use of such a technique during picking would help to assure that consistent quality is being delivered to marketers, retailers, and consumers. Sonic and vibration response method is one technique for predicting the textural quality of agricultural products non-destructively. Experiments on use of this technology to symmetrical fruits, like melons and water-melons, have been reported. In the present study, a non-symmetrical fruit, i.e., mango was used to determine whether it can be used or not? Orientation of the mango fruit is important to have reliable data. It was also found that the best place to measure firmness by Acoustic Firm Tester is the thick flat pulpy side of the mango fruit. This tester would be beneficial especially in those countries where retail price of locally produced fruits is very high due to high cost of production, and also to other countries where quality is given prime importance.

Fungicidal Effect of the Mixed Atmosphere of Ozone and Negative Ions on Fruit Rot of European Pears

Abstract The effect of mixed atmosphere of ozone and negative ions (MAONI) exposure on in vitro growth of Botryosphaeria berengeriana (de Notaris) and development of postharvest fruit rot on artificially inoculated European pear fruit, cv. La-France, were evaluated. In vitro mycelial plugs and pears, in separate experiments, were continuously exposed to MAONI (0.05 ppm ozone and 2.8x106 negative ions/cm3) at 4°C for 4, 8, 12, and 16 days, in a specially fabricated MAONI chamber, and then shifted to 20°C. In vitro radial growth of B. berengeriana during 5-day incubation period at 20°C was affected by the prior MAONI exposure. The 16 days MAONI exposure significantly reduced the growth of B. berengeriana and fruit rot disease.