THE ANTIOXIDATIVE ACTIVITY OF SUMMER SAVORY (SATUREJA-HORTENSIS L) AND ROSEMARY (ROSMARINUS-OFFICINALIS L) IN DRESSING STORED EXPOSED TO LIGHT OR IN DARKNESS

For an oil-in-water emulsion dressing, addition of 0.15% of dried leav es of summer savory (Satureja hortensis L.) or more significantly of r osemary (Rosmarinus officinalis L.), resulted in a significantly bette r antioxidative protection than addition of 80 ppm propyl gallate (sta ndard concentration for this type of product) during dark storage at 1 9 degrees C for up to 24 weeks, as determined by development of conjug ated dienes, peroxide value, head space hexanal and thiobarbituric aci d-reactive substances. Addition of freeze-dried methanol extract of th e two spices, in an equivalent concentration, had less antioxidative e ffect, but was comparable to the effect of propyl gallate. Exposure to fluorescent light (850 lux) during storage had a clear pro-oxidative effect for dressing with or without spice or spice extract added, when compared to dark storage. For dressing with extract of savory added, the antioxidative effect found for dark storage was during light expos ure, changed to a pro-oxidative effect, and a hexanal level as high as 600 mg kg(-1) oil was detected after 8 weeks of storage, while the ne t antioxidative effect of rosemary was maintained for storage exposed to light. (C) 1998 Elsevier Science Ltd. All rights reserved.