Addition of high esterification pectin as a stabilizer in the production of low fat yogurt

Abstract

A shake-type low-fat yogurt prepared with highly esterified pectin extracted from valence orange by acid hydrolysis with conventional heating was evaluated. A completely randomized design was used with experimental and commercial pectin (0.15, 0.3, 0.45%), and a control. Cow's milk was adjusted to 1.5% fat, with skimmed milk powder and pasteurization at 85oC, 30 min and sucralose and lyophilized lactic culture were added with stirring, until acidity 0.58% and pH 4.74. Pectin was added as a stabilizer and subsequent refrigeration and storage at 5oC ± 1oC. Acidity, pH, syneresis and viscosity were evaluated for 28 days and sensory analysis by seven trained judges (NTC 4129), ten days after the yogurt was elaborated, using discriminatory test of multiple comparisons. The highest acidity and syneresis was found in the control and the two pectins (commercial and experimental) behave the same at equal percentages. Treatment with 0.15% and 0.3% of experimental pectin show a color close to the control and show slight statistical differences between them. Yogurt with less than 0.3% pectin presents an identical flavor to the commercial one and higher ones present differences with the control and affect the final flavor of the product. Yogurt with 0.3% experimental pectin presents a body without lumps, without syneresis, firm and smooth consistency, maintains the characteristic smell, aroma and flavor and meets the requirements of the NTC 805 standard, with a maximum of 0.5% fat, minimum of 2.6 % protein and 0.6% acidity with a shelf life of 22 days.