Sesame (Sesamum indicum L) is one of the oldest cultivated plants. Its seed contains about 42-54 % quality oil, 22-25 % protein, 20-25 % carbohydrates and 4-6% ash. This composition varies with genetic and environmental factors. Conditioning of oil seeds which include roasting, flaking, size reduction, cooking, pre-pressing and drying, is an important operation in the production line of sesame oil. This work investigated effects of initial moisture content, roasting duration and temperature on initial Peroxide Value (PV) and Oxidative Stability (OS) of unrefined sesame oil using response surface methodology. Goza-25, a variety of sesame seed that is commercially cultivated in Nigeria was used for the study. Initial moisture content levels were 4, 7, 10, 13 and 16 % wet basis (wb). Roasting duration and temperature levels were 5, 10, 15, 20 and 25 minutes, and 50, 70, 90, 110 and 130 o C respectively. The recorded minimum and maximum PV were 3.9 and 15.4 meq/kg respectively. Mean value was 9.85 ± 3.9 meq/kg. Peroxide value increased with increasing moisture content and reduced with increasing roasting duration. Analysis of variance and regression analysis of obtained data showed that application of quadratic model to predict effect of initial moisture content, roasting duration and temperature on peroxide value is significant at p ≤ 0.05. Within the studied range, 13 h was the minimum OS recorded while maximum were 63.3 h. Mean of the data was 38.37 ± 16.02. Using the conversion factor of one hour of an active oxygen hour as being equivalent to 15 days; the expressed sesame oil in its present form will retain its quality for a maximum period of 949 days. Rise in roasting temperature and duration increased the oxidative stability, a reverse was observed with initial moisture content. High moisture content reduced the quality and storage life while heat treatment increased both the initial quality and storage life of the mechanically expressed oil. Peroxide value and oxidative stability of crude sesame oil significantly (p ≤ 0.05) depend on moisture content of the seed, roasting duration and temperature.

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The current study reports the effects of waste glass additives on the properties and compliance level of fired ceramic masonry bricks. In the course of producing durable bricks for masonry, waste glass powder sieved to 150 μm was added to clay, mixed with water and fired to 1000°C. The effects of the waste glass addition were investigated by subjecting 242 ceramic bricks produced to physical, mechanical, and thermal tests. Their morphological behaviour was thereafter examined. From the results obtained, the physical and mechanical properties were improved as waste glass content increased in the samples. Values of properties obtained were compared with existing standard values for bricks and it was observed that compliance level at 0% waste glass was 63%, at 10% waste glass addition, it was 75% and at 15% to 40% waste glass addition, compliance was 100%. Therefore, it was concluded that waste glass addition to bricks improved the properties of bricks for construction purpose.

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