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factors that are known to produce variability, is vital in food research. 1 Conventional electric ovens are often used for food research purposes at research laboratories. 2 Conventional electric ovens usually have capillary thermostats and can consequently have a wide variation in average oven temperature, and long heating and cooling cycles. Standard specifications for conventional electric ovens require that the average internal temperature at each thermostat setting should not differ from the temperature indicated on the thermostat by more than 10°C. 3 This requirement has become the standard in many countries. In ovens with a variation in average oven temperature of 10°C, the average length of the cooling and heating cycle is approximately 5 min. 4 The latter variation in average oven temperature and time for the heating and cooling cycles is very crude and can result in a significant percentage variation with replication of treatments.Some researchers have attempted to control conditions during baking by using ovens designed and built by themselves. 5-7 A good example of temperature control can be found in the research aimed at the development of a highly reproducible conventional microwave oven for development work commissioned by the Food Refrigeration and Process Engineering Research Centre at the University of Bristol. This research was undertaken as a result of the non-repeatability of conventional microwave ovens. The system is designed to eliminate the factors that are known to produce variability and it will provide repeatable conditions so that any variations in heating will be due to differences in the foods themselves and not due to changes in the oven conditions arising from differences in the cavity or power supply. 8 The American Association of Cereal Chemists' approved methods 9 stipulate that reel or rotary ovens (gas or electric) used for baking tests must have level baking surfaces and be capable of temperature control to ± 2°C or less at 200°C. AbstractA more sophisticated temperature control system than the capillary thermostat in conventional electric ovens is necessary for laboratory research on foods. The aim of the study was to develop a computerized temperature control system (CTCS) for conventional electric ovens and to determine whether the CTCS could effect comparable and consistent results in two ovens with regard to oven and product characteristics of baked products. No significant differences were found between the two ovens with regard to average oven temperature, texture and height of products. In most instances there were also no significant differences between the ovens with regard to instrumental colour measurement and moisture loss. The regression results also illustrated the effectiveness of the CTCS, i.e. that an increase in set oven temperature of 1°C has a significant effect on specific oven and product characteristics. The CTCS therefore significantly improved the reproducibility of quality characteristics of baked products. Thus, more consistent and repeatable re...

In food research, temperature is one of the variables that must be controlled at all times; household electric ovens are often used for this purpose. The aim of this study was to determine whether an electronic temperature controller (ETC) – an electronic apparatus with a solid‐state switch and sensitive sensor – can provide improved temperature control, and consequently sustained food quality, compared with a capillary thermostat in a household electric oven. It was found that the ETC is indeed able to provide better temperature control in household electric ovens. It can, therefore, make a valuable contribution to food research, where consistency during replication is vital for the reliability of research results.

Die doel van die studie was om 'n kontrolestelsel te ontwikkel wat die gemiddelde oondtemperatuur van twee konvensionele elektriese oonde beheer, en om te bepaal of die kontrolestelsel tussen en binne oonde vergelykbare en herhaalbare resultate lewer betreffende gemiddelde oondtemperatuur en die kleur, vogverlies, hoogte en tekstuur van kleinkoekies en laagkoeke soos bepaal deur objektiewe meetinstrumente. Geen betekenisvolle verskil is gevind tussen en binne behandelings wat die gemiddelde oondtemperatuur en die meeste produkeienskappe betref nie. Hierdie beheerstelsel kan dus vir voedselnavorsing aanbeveel word. Dit verbeter temperatuurbeheer binne en tussen konvensionele elektriese oonde en kan 'n sinvolle bydrae tot eksperimentering in voedselnavorsing lewer waar konstantheid tydens die herhaling van behandelings van kardinale belang vir betroubare resultate is.