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Apparatuses | Biochemistry, Food Science and Nutrition

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Head of Institute: Prof. Ido Braslavsky

Administrative manager: Rakefet Kalev

Office Address:
Institute of Biochemistry, Food Science and Nutrition,
Robert H. Smith Faculty of Agriculture, Food and Environment,
The Hebrew University of Jerusalem, 
Herzl 229, Rehovot 7610001, ISRAEL

Tel: +972 - (0)8-9489385
Fax: +972 - (0)8-9363208
Email Address: rakefetk@savion.huji.ac.il

Apparatuses

Gloss measurements of flat and smooth surfaces

We have succeeded in building a new type of glossmeter with the following attributes: the option to accurately check the gloss properties of non-flat surfaces, such as those of fruits and vegetables; the ability to change the angle of illumination; the use of a helium-neon laser for illumination; the ability to collect data from a three-dimensional body by scattered light beams in real time, special software for data analysis capable of computing the effects of reflected light from a curved surface. In other words, the computer gives a single number representing the gloss of the curved surface, by using appropriate analysis techniques.

A. Nussinovitch and E. Mey-Tal. Glossmeter. U.S. patent #6,018,396 and Israeli patent #109,033.

G. Ward and A. Nussinovitch (1996). Peel gloss as a potential indicator of banana ripening. Lebensmittel-Wissenchaft und-Technologie, 29 (3), 289-294.

Crunchmeter for the quality control and development of crunchy foods

A novel instrument has been developed that is capable of evaluating the crunchiness of food products such as cereals, waffles, snacks, noodles, sugar cubes, croutons, and more. Besides edible materials, it can also be applied to determine the "crunchiness" of other substances, such as biological and synthetic (e.g. packing) materials. The apparatus, which was described by "New Scientist" as an outstanding significant achievement, is based on the crushing of a test substance. The device can be attached to a conventional Universal Testing Machine, which is used to determine mechanical properties of semi-solid and solid foodstuffs as well as other materials. After the crushing has been performed, evaluation is carried out using an appropriate algorithm and a numerical result is obtained. The measurement is performed over a short time period and can be adapted to on-line use. Furthermore, an indication of the degree of humidity in the substance can be obtained.

A. Nussinovitch and E. Mey-Tal (1998). System for measuring the crispiness of material crunchmeter. U.S. patent #5,827,974.

Apparatus for the continuous monitoring of gel swelling and shrinkage gels and of colored solutions

This machine can follow continuous changes in the swelling and shrinkage of gels or other physical bodies, give information on changes in color reactions in real time, and follow changes at the microbial level of microorganisms as evidenced by loss of clarity. Special software and sample cells have been built for these purposes. The advantage of this apparatus is the continuous report it provides while tracing the aforementioned processes in real time.

A. Nussinovitch, N. Peleg and E. Mey-Tal (1995). Continuous monitoring of changes in shrinking gels. Lebensmittel-Wissenchaft und-Technologie, 28 (3), 347-349.

Electrical drying of foods

A custom-made apparatus was built in our lab to permit the electrical drying or partial drying of foods. The method has proven successful at an experimental level. Pieces of vegetables were contracted, showing a decrease in volume and weight of up to ~85% of their initial values. We are currently optimizing this method, scaling it up, studying its limitation and investigating of changes in enzymatic activity during and after operation. The commercial advantages of the method are its simple, quick, clean and inexpensive operation, drying without stiffening the tissue and control over changing the tissue's porosity. The new drying method could provide an alternative way of producing small pieces of dried vegetative materials for soups, to be mixed with spices and noodles, and for other food uses.

R. Zvitov and A. Nussinovitch (2001). Weight, mechanical and structural changes induced in alginate gel beads by DC electric field. Food Hydrocolloids, 15, 33-42.

Novel method and apparatus for testing the rolling-tack of pressure-sensitive adhesive materials

A novel method and custom-made apparatus for testing the tack of pressure-sensitive adhesives and related materials were developed to simplify the measurement of bonding and debonding processes. Ease of execution and high reproducibility enable their use to study the experimental tack of adhesive materials.

O. Ben-Zion and A. Nussinovitch (2002). Testing the rolling tack of pressure-sensitive materials. Part I. Novel method and apparatus. J. Adhesion Sci. and Technol., 16 (3), 227-237.

O. Ben-Zion and A. Nussinovitch (2002). Testing the rolling tack of pressure-sensitive adhesive materials. Part II. Effect of adhered surface roughness. J. of Adhesion Science and Technology, 16, 597-617.