Basil S. Kamel

Improving the Quality of Used Frying Oils by Treatment with Activated Carbon and Silica

This study was undertaken to investigate the effectiveness of activated carbon and silica in removing the degradation products present in used frying oils. Two batches of canola oil were treated with mixtures of activated carbon and silica. Three levels of activated carbon (3%, 6%, 9%, wt/wt) were blended with three levels of a silica compound (2%, 4%, 6%, wt/wt) in all nine possible combinations. Oil 1 was prepared by continuous heating in the lab, and oil 2 was obtained from a small potato-frying operation. For each treatment combination of silica and carbon, the average percent decrease for acid value, peroxide value, photometric color, polar compounds, saturated carbonyls and unsaturated carbonyls was 53.9%, 39.4%, 38.3%, 27.5%, 54.0% and 27.3%, respectively, for oil 1, and 51.1%, 53,5%, 49.7%, 16.3%, 58.9% and 39.0%, respectively, for oil 2. The levels of oleic, linoleic and linolenic acids decreased by 28%, 33% and 35%, respectively, following heat treatment but were shown to increase by 1 to 5% after adsorbent treatment. The yield of treated oil ranged from 56 to 83%.

Characteristics of bread and buns made with lard and vegetable oils of different iodine values

A good-quality white loaf of bread or rolls can be baked by substituting liquid vegetable oil (canola, soya and palm) for the standard shortening,i.e. lard, tallow or partially hydrogenated vegetable shortening. Canola oil and soya oil produced lower specific volumes of 5.56 and 5.55 cm3/g and higher softness indices when used with mono- and diglycerides only. Palm oil and lard produced specific volumes of 6.33 and 6.15 cm3/g and lower softness indices with mono- and diglycerides. When a blend of surfactants consisting of mono- and diglycerides and sodium stearyl lactylate (SSL) was used at 0.5% of flour weight, palm, canola, lard and soya gave comparable results in specific volume and compressibility. Rolls baked with the same fats and oils, and addition of ethoxylated stearic acid (MYRJ 45H) or a blend of MYRJ 45H and SSL, all gave good specific volumes ranging from 6.92 to 7.27 cm3/g and a softness index range of 0.71–0.86 and 0.68–0.86 after 48 and 96 h of storage. When a proper surfactant is used, good-quality bread and rolls can be baked with liquid vegetable oil. Furthermore, the usage level of liquid oil can be cut by approximately 30% in comparison to lard or shortening while still maintaining quality.

Composition and Properties of Bean Curd Made from Ontario Soybeans

Abstract Eleven varieties of Ontario grown soybeans were analyzed for protein, phosphorus and moisture content. The beans were processed into soymilk and bean curd prepared by coagulation with calcium chloride. Curd and protein yields were determined. Calcium chloride, sulfate and acetate were satisfactory for curd precipitation, but calcium citrate was not. Hardness of the curd was measured by compression in the Instron Universal Testing Machine. Rheological properties determined by creep testing included instantaneous and retarded elasticity as well as viscous flow. Moisture content of the bean curd is an important variable influencing the rheological properties.

Measurement of Fat Consistency by the Penetration Method.

Abstract Three different types of punches were used to test fat consistency in a penetration test: Bloom, Kruisheer and den Herder and a set of flat-end cylindrical punches. The use of Bloom type punches did not give useful results because there was no distinct yield point in the force-distance curves. With both Kruisheer and den Herder and the flat cylindrical punches a definite yield point was obtained. The relationship between punch area and force was a straight line going through the origin with normal and soft margarines. The relationship between punch perimeter and force was not linear. The effect of penetration speed and the relationship between the nature of the curves and the physical structure of the food is discussed. It was concluded that penetration tests of products such as normal and soft margarine with a weakly bound network structure involve flow as the major factor.

A Dynamometer Instrument for Measurement of Textural Characteristics of Foods

Abstract An electronic dynamometer is described for measuring the power input to food processing systems. It is a gearbox in which one of the moving components is held stationary by a strain gage force transducer. A texture measuring instrument was constructed in which a food can be forced through one or more perforated plates and given additional mechanical treatment by an impellor rotating behind the plates. The forces on the two drive shafts are measured by two of the dynamometers. Texture measurement on dates is used as an example of the functioning of the apparatus.