LAURA PAULINO MARDIGAN

Título da Tese: Avaliação dos nutrientes e compostos bioativos nas variedades de abacate (Persea americana Miller) e desenvolvimento de produto alimentício

Orientador: Prof. Dr. Makoto Matsushita

 Data da Defesa: 05/02/2018

RESUMO GERAL

Avocado, a fruit from a perennial leaf tree that grows better in a warm climate, can reach up to 20 m in height, providing fruits of 250 g to 1.5 kg. The cultivars are divided into three groups, Mexican (Persea Americana variety drymifolia), Guatemalan (Persea Americana guatemalensis variety) and Netherlands Antilles (Persea Americana American variety). The varieties chosen for this study were Breda, Choquette, Margarida, Ouro Verde and Quintal of Mexican origin. These fruits have on average 70% in pulp, and has considerable nutritional quality, with a high level of fiber, protein, β-carotene, and minerals, especially iron. The lipid fraction presents good characteristics in fatty acids, mostly monounsaturated oleic (Omega 9), and a high concentration of sterols which together are able to positively influence the metabolic control of cholesterol. The avocado oil properties are similar to olive oil, providing an alternative to offer the consumers a mixed product with superior quality to soybean oil. Highlighting, tocopherols (vitamin E) and antioxidants, important substances that act by inhibiting and/or decreasing the effect triggered by free radicals, where the excess produces cell imbalance initiating the oxidative stress, responsible for various types of chronic degenerative diseases. The objective of this study was to evaluate the nutritional quality of the varieties of avocado pulp through the proximal analysis, antioxidant activity, carotenoids, triglycerides, fatty acids and the development of a product containing avocado pulp enriched with chia oil. The samples were subjected to humidity analysis (962.09 methods), ashes (945.38 methods), crude fiber (971.09 methods), crude protein (962.09 methods), carbohydrates by difference, the determination of total lipids was analyzed by the Bligh and Dyer method, fatty acids were analyzed in gas chromatograph Thermo Trace Ultra, equipped with capillary column and flame ionization detector and the triacylglycerol using EASI-MS (LCMS-2010 EV – Shimadzu). Carotenoids were measured by UV-vis spectroscopy at 450 nm, and antioxidants evaluated by DPPH test (2,2 diphenyl-1-picrylhydrazyl), ABTS (2,2’-azino-di-(3-ethylbenzothiazoline)-6-sulfonic acid), FRAP (Ferric Reducing Antioxidant Power), fluorometric ORAC (Oxygen Radical Absorbance Capacity) e L-ORAC. The antioxidant capacity and the fatty acids composition were evaluated and the results show that all the varieties are constituted mainly of monounsaturated fatty acids (60%) being the oleic acid majority. Breda variety demonstrated the highest antioxidant activity for the DPPH test (1.1200 µmol ET/g), Quintal variety for ABRS, Ouro Verde for the ORAC test (23%), and the Margarida for the L-ORAC test (200 µmol ET/g). These results suggest that the fruit studied represents a source of antioxidants, due to the significant results achieved by the tests. For the development of the products (salad dressing enriched with chia oil) the experimental design was held by 22 (two factors at two levels) with central point to investigate the influence of proximal composition and fatty acids composition for the salad dressing. The two factors were: avocado pulp concentration and chia oil. The factorial design generated five formulations and the formulation number five was the central point. The proximal composition results and fatty acids were analyzed by principal components analysis (PCA). The chemometric method used to evaluate the factors were significant for the formulations. The factors evaluated have contributed positively to the composition of total lipids, proteins, fibers, and fatty acids. The principal components analysis distinguished the samples with the highest content of fiber, protein, and total lipids as well as the fatty acids composition. Therefore, it can be observed that the avocado pulp is a food with high levels of antioxidants and oleic acid, and the product’s development is an alternative 10 food that may contribute to health since it has a significant amount of nutrients and alphalinolenic acid (Omega 3). Key words: antioxidant activity, Chemical composition, oleic acid, alpha-linolenic acid, chemometrics.

Artigos Publicados Vinculados a Tese:

https://doi.org/10.1590/fst.34817