INFLUENCE OF PARTIAL SUBSTITUTION OF SUGAR WITH SERENDIPITY BERRY (DIOSCOREOPHYLLUM CUMMINSII) EXTRACT ON THE QUALITY ATTRIBUTES AND SHELF-LIFE OF WHEAT BREAD

Abstract

Serendipity berry (Dioscoreophyllum cumminsii) contains a protein sweetener termed monellin which could be substituted for sugar in foods for diabetics and dieters. Therefore, effects of partial substitution of sugar with serendipity berry extract on quality of white wheat bread were investigated. The pasting properties of wheat flour treated with mixtures of 5 % sugar solution and serendipity berry extract (100:0 control, 80:20, 70:30, 60:40, 50:50 and 40:60) were investigated. Wheat flour were blended with other ingredients and mixtures of 5 % sugar solution and serendipity berry extract to form dough which were allowed to rise prior to baking. Chemical, microbiological and sensory properties of the breads were evaluated. Pasting temperature, peak, final and setback viscosities of the control (sugar solution treated-flour) and serendipity extract treated flour were significantly (p˂0.05) different. Moisture, ash, protein, fat, fibre and carbohydrate contents of the breads ranged from 11.93–15.22 %, 0.75–3.06 %, 11.67–14.13 %, 4.29–9.06 %, 1.24–2.50 % and 55.01–68.14 %, respectively. Although the bacterial (0.0–61 ×103 cfu/g) and fungal (2.0–76.0 ×103 cfu/g) counts of the breads increased throughout the 5 days storage period, the serendipity berry extract exerted antimicrobial activities in the treated breads. The proximate, except carbohydrate, of the breads increased while the bacterial and fungal counts decreased with increase in concentration of the serendipity extract. The 60 % serendipity extract treated-bread (mean sensory scores ≥ 8.0) compared favourably with the control (sugar solution treated-bread). This study revealed that 60 % serendipity berry extract could be substituted for sugar for production of high quality bread with extended shelf life.