The effect of gamma radiation on chia (Salvia hispanica L.) edible film

Abstract

Edible films and coatings have received considerable attention in recent years for their advantages over synthetic films for edible packaging materials. Chia seeds (Salvia hispanica L.) have functional and important nutritional values: protein content (15–25%), fats (30–33%), carbohydrates (26–41%), dietary fiber (18–30%), and ash (4-5%). It also contains a high amount of vitamins, minerals, and antioxidants. Mucilage of chia, a natural exudates from chia seeds, is mainly composed of xylose, glucose and glucuronic acid forming a branched polysaccharide. In the present preliminary work whole chia seeds were irradiated in a 60Co source Gammacell 220 (AECL) with doses of 0, 5 and 10 kGy, dose rate about 0.8 kGy h-1. The irradiated seeds were crushed and soaked in an aqueous solution (6% w/w) together with glycerol (1% w/w), under magnetic stirring for 15 minutes at room temperature and poured into casting plates. The plates were placed in an oven with forced air circulation at 35 °C for at least 20 h. Water uptake, moisture, solubility and water activity of the films were established. The most expressive result was a decrease in water uptake with the increase of the radiation dose. Solubility remained almost unaffected by radiation in doses of 5kGy and moisture analysis showed also a decrease with dose.