In vitro bioavailability of Beta-carotene from cassava and sweet-potatoes biofortified in Brazil: study of the effects of genotypes and processing

Author(s)

Paulo Roberto de Araujo Berni

• Document type: Master's Dissertation
• Press: Piracicaba.
• Institution: Universidade de São Paulo (USP). Centro de Energia Nuclear na Agricultura (CENA/STB)
• Defense date: 2014-07-08

Examining board members

Solange Guidolin Canniatti Brazaca; Adriana Zerlotti Mercadante; Teresa Losada Valle

• Advisor: Solange Guidolin Canniatti Brazaca

Abstract

Vitamin A deficiency is a world public health problem that affects especially infants, children less than 5 years of age, women during birthing and 1 year post-partum and is the primary cause of avoidable blindness in children. Biofortification is a strategy aimed at decreasing global micronutrient deficiencies in vulnerable populations by increasing the nutrient density in staple food crops. It was investigated the effects of genotype and cooking styles on the content, retention and bioavailability of ?-carotene (?C) in biofortified cassava and orange fleshed sweet-potatoes (OFSP). Five genotypes of biofortified cassava, three parental accessions, and one white cassava were provided by two different breeding programs. Additionally, two genotypes of OFSP and two brands of high processed baby foods were evaluated. Both cassava and OFSP roots were analyzed raw, after boiling in water at 100°C only or after subsequent frying in soybean oil at 180°C. Carotenoids were extracted and analyzed by HPLC-DAD. Bioavailability was assessed using an in vitro oral, gastric and small intestinal digestion coupled with the Caco-2 human intestinal cell model. Only ?C was detected in all tested genotypes of cassava root, although its content varied markedly depending on genotype. Biofortified genotypes contained at least 10-fold higher ?C than the white variety. Boiling and frying were associated with loss and isomerization of ?C in cassava as well as OFSP. There was an interaction of genotype and cooking style on profile of ?C contents. Efficiency of micellarization of trans-?C in boiled cassava was lower than in fried. Biofortified cassava ready to eat can provide up to 28% of the IDR of retinol. Uptake of trans-?C in micelles generated during digestion by Caco-2 cells was analyzed for the four of the five biofortified genotypes. Cell uptake of ?C from two genotypes were not affected by processing, however the other two genotypes had increased with frying. Regarding sweet-potatoes, trans-?C was the major carotenoid found, although it was identified three ?C isomers and ?-carotene in minimal quantities. The concentration of trans-?C in one genotype of OFSP was two times higher than baby foods and the other genotype. Baby foods had relative presence of the 13-cis-?C higher than in the OFSP. Efficiency of micellarization of trans-?C from cooked OFSP or Baby foods was considered low, and had no statistic differences between boiling and frying. The Caco-2 cells uptake were not different for the genotypes and baby foods investigated. The absolute amount of accumulated trans-?C intracellular was proportional to the concentration of the starting material. In summary, biofortified crops can increase ?C contents in diet. Fried cassava presents more bioavailable ?C than boiled. Cassava genotype and cooking style may influence uptake of trans-?C by absorptive intestinal cells. In contrast, there is no evidence that high processed OFSP has more bioavailability of ?C than homemade boiled or fried OFSP (AU)

• FAPESP's process: 11/16086-6 - Profile and bioavailability of provitamin A on biofortified cassava varieties
• Grantee: Paulo Roberto de Araujo Berni
• Support type: Scholarships in Brazil - Master