Development of a Peanut-Sweetpotato Ready to Use Therapeutic Food and Evaluation of Peanut Skins in Peanut Products.

摘要

Severe acute malnutrition (SAM) affects 20 million children under the age of five. Vitamin A deficiency (VAD) is the leading cause of childhood blindness in the world and an estimated 250,000 to 500,000 children become blind every year. Ready to use therapeutic foods (RUTF) are soft enriched foods containing mostly peanuts, milk powder, and vitamin/minerals. RUTFs were developed to eliminate SAM and incorporating beta-carotene rich sweetpotatoes in RUTFs may be a viable way of addressing VAD. The main objective of this work was to develop a peanut-sweetpotato RUTF and evaluate nutritional composition, descriptive sensory analysis and consumer acceptance of formulations containing peanuts/sweetpotato flakes (SPF)/milk powder, and other standard ingredients. A secondary objective was to evaluate the potential of peanut skins to improve nutritional properties and enhance the shelf life of peanut products.;Eleven formulations of peanut paste fortified with SPF and milk powder were evaluated for nutritional composition and sensory characteristics. A lexicon incorporating roasted peanut and sweetpotato flavor descriptors was developed. Increased beta-carotene and oxidative stability index (ORAC) were observed in the test formulations. In the samples evaluated, beta-carotene ranged from 230 to 3870 microg/100g, while ORAC ranged from 4030 to 5025 microMol/100g. The addition of milk powder improved protein quality, resulting in increased concentration of some specific amino acids. From the eleven formulations, two were selected for the evaluation of nutritional composition, flavor using descriptive sensory analysis and consumer acceptance. A commercial RUTF (MANA), and one peanut only formulation were evaluated. The three formulations contained 49/15/20, 28/20/30 and 56/0/30 percentages of peanuts/SPF/milk powder, respectively, and other standard ingredients. beta-carotene in 49/15/20 and 28/20/30 was 2040 microg/100g and 3070 microg/100g, respectively. MANA and the 56/0/30 formulation contained 350 microg/100g and 420 microg/100g, respectively. The combination of milk powder with other ingredients used in this study resulted in a more complete amino acid profile than peanuts alone. Formulations containing SPF were characterized by roast peanutty, sweet aromatic, baked sweetpotato/dried apricot/floral aromatics. The formulation containing 15% SPF was one of the two most overall liked by consumers and overall flavor liking was highest in this formulation.;To potentially add antioxidants to RUTF's, peanut skins were incorporated into peanut paste and peanut butter. Peanut skins blended up to 20.0% w/w resulted in increased (P<0.05) total phenolic content of peanut paste from 12.9 to 31.9 mg/GAEg and 14.1 to 28.1 mg GAE/g for peanut butter. Oxygen radical absorbance capacity (ORAC) of peanut paste and peanut butter increased as the concentration of peanut skins increased, and ranged from 4041 to 20063 and 5702 to 20376 microMol Trolox/100g. The addition of low levels of skins did not result in flavor changes but more than 5% peanut skins resulted in a decrease in roast peanut intensity and an increase in woody/hulls/skins, bitter and astringency intensities.;Subsequent storage of peanut paste and peanut butter containing skins resulted in a decrease in shelf life inversely related to the concentration of peanut skins added. A study was conducted to identify the cause of reduced shelf life. Oxidative stability index (OSI) of peanut skin oil (1.1-4.1 hrs) was significantly lower (P<0.05) than oil from peanuts (9.8 -- 15.7 hrs). Analysis of peanut skins indicated low levels of alpha-tocopherol and high levels of Cu and Fe. OSI, low alpha-tocopherol, and high copper and iron concentrations in peanut skins suggest a cause for reduced shelf-life of peanut products containing peanut skins.