Centesimal Evaluation of Two Species of Ora-pro-nobis (pereskia Aculeata Miller and Pereskia Grandifolia Haw) and Application in Extruded Product

Abstract

Some vegetables that are rarely used and/or unknown in daily menu, can represent great sources of vital nutrients to maintain metabolic health of their consumers. Among them is Pereskia spp family, commonly known as ora-pro-nobis, the flesh of poor. According to RDC No. 54/2012 (BRASIL, 2012), Ora-pro-nobis can be considered a functional food due to its high protein content (approximately 25%), with high digestibility (80%), 3.35g/100g of calcium, 2.42g/100g of potassium, 1.13g/100g of phosphorus, 0.45g/100g of magnesium and 0.98g/100g of sulphur, leaf (140.36 ppm) and stem (88.75 ppm) iron. These data also meet antioxidant characteristics of plant. Studies have shown that extracts, both leaves and stems, have a high content of restive compound to oxygen, given characteristic of antioxidants. Considering high nutritional value of this plant, objective of this study was to verify bromatological composition of Perskia aculeata Miller and Pereskia grandifolia Haw leaves, as well as, evaluate extrusion of flour of its dehydrated leaves in proportion of addition of 10% together with corn, in order to evaluate possibility of its processing. Extrusion tests were performed using 100 grams of sample containing 10% of dehydrated leaf completed with corn grits, obtaining extruded samples of CPA (Pereskia aculeata Miller), CPG (Pereskia Grandfolia Haw) and 100% corn grits (CP) as standard for comparison. Samples were pre-stored at humidity of 20% prior to process, which occurred steadily, without changes in extruder parameters. Subsequently, final extruded product was homogenized and dried in a rotary mixing drum at 60°C. Extrusion cooking was performed in duplicate using IMBRA RX50 (INBRAMAQ, Ribeirao Preto, SP, Brazil), with a single thread of 50 mm in diameter and 200 mm in length. The die set used had two 3 mm diameter holes and parameters were set with motor amperage at 20A and feed rate of 15g/s with a cut at 120rpm. Sample were evaluated regarding ethereal extract, determined by continuous extractor method Soxhlet type, crude protein, measured by Kjeldahl method (conversion factor 6.25 (N x 6.25)), ashes were obtained by incineration (550 oC) in muffle furnace, crude fibres, fibres in neutral detergent and acid detergent, total phenolic compounds (DPPH) and FRAP for antioxidant potential. Results demonstrated nutritional viability of two species, Pereskia aculeata Miller and Pereskia grandifolia Haw, in their bromatological parameters. Inclusion of dehydrated leaves in extruded products demonstrated as viable and results showed that final product has satisfactory nutritional characteristics, with substantial increase of protein, iron, fibres and antioxidant capacity in relation to standard product.