[Development of an optimized formulation of damask marmalade with low energy level using Taguchi methodology]

The goal of this present study was the development of an optimized formula of damask marmalade low in calories applying Taguchi methodology to improve the quality of this product. The selection of this methodology lies on the fact that in real life conditions the result of an experiment frequently depends on the influence of several variables, therefore, one expedite way to solve this problem is utilizing factorial desings. The influence of acid, thickener, sweetener and aroma additives, as well as time of cooking, and possible interactions among some of them, were studied trying to get the best combination of these factors to optimize the sensorial quality of an experimental formulation of dietetic damask marmalade. An orthogonal array L8 (2(7)) was applied in this experience, as well as level average analysis was carried out according Taguchi methodology to determine the suitable working levels of the design factors previously choiced, to achieve a desirable product quality. A sensory trained panel was utilized to analyze the marmalade samples using a composite scoring test with a descriptive acuantitative scale ranging from 1 = Bad, 5 = Good. It was demonstrated that the design factors sugar/aspartame, pectin and damask aroma had a significant effect (p < 0.05) on the sensory quality of the marmalade with 82% of contribution on the response. The optimal combination result to be: citric acid 0.2%; pectin 1%; 30 g sugar/16 mg aspartame/100 g, damask aroma 0.5 ml/100 g, time of cooking 5 minutes. Regarding chemical composition, the most important results turned out to be the decrease in carbohydrate content compaired with traditional marmalade with a reduction of 56% in coloric value and also the amount of dietary fiber greater than similar commercial products. Assays of storage stability were carried out on marmalade samples submitted to different temperatures held in plastic bags of different density. Non percetible sensorial, microbiological and chemical changes were detected after 90 days of storage under controlled conditions.