Abstract

Atriplex hortensis L., also known as orach, is a leafy vegetable from the Amaranthaceae family, which has historically been consumed as a potherb, like spinach. The brightly colored leaves are a source of high quality protein, but may also be of interest as a potential source of natural food pigments. An aqueous extraction was obtained from the freshly harvested leaves of the'Triple Purple' variety of A. hortensis. The extract was spray-dried into a powder, and individual pigments were analyzed using HPLC and LC-MS. The powder was also included as a color additive in a typical stabilizer/sweetener preparation and mixed into plain yogurt. Two batches of colored yogurt were held under light and dark conditions and tested for pH and color (L*a*b*) every 15 days. A visual sensory panel was performed on days 0, 45, and 90 to evaluate the color acceptance.A total of three types of betacyanins and six types of anthocyanins were tentatively identified by HPLC and/or LC-MS. Orach pigments in yogurt were not stable under full light exposure. The color of samples exposed to light degraded within days. There were statistically significant differences found in L*a*b* scores in the dark treatment, beyond 30 days; but these modest changes in dark-stored samples were not found to be statistically significant in the consumer sensory panel. The tentative identification of both anthocyanins and betacyanins in orach is a novel finding in botanical research, as the literature indicates that these two pigment classes are mutually exclusive. The application of heat during pigment extraction, spray drying, and yogurt color additive preparation, did not appear to appreciably affect stability of orach pigments, indicating that orach extract could be used as a color in different process applications, if protected from light.

Degree

College and Department

Life Sciences; Nutrition, Dietetics, and Food Science

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