Studies of chemical and enzymatic characteristics of Yacon (Smallanthus sonchifolius) and its flours

Abstract

Due to the importance of studies on yacon related to health, its in natura pulp, in natura peel, pulp flour, and peel flour were chemically analyzed in terms of its centesimal composition, specific minerals, total dietary fiber and fractions, pH, total soluble solids, total titratable acidity, tannins, oxalic acid, and nitrate. The polyphenoloxidase and peroxidase enzymatic activities were evaluated for in natura pulp and peel only. Yacon pulp and peel flour presented average yield of 7.94% and 10.86%, respectively. The in natura pulp presented a higher moisture and carboydrate content and lower lipid, protein, total dietary fiber, and ash than those of the peel flour. The same pattern was observed for pulp flour when compared to peel flour. The highest tannin, nitrate, and oxalic acid levels were found in the peel flour, 15,304.5 mg.kg-1, 1,578.3 mg.kg-1, and 7,925.0 mg.kg-1 (wet weight), respectively. The polyphenoloxidase and peroxidase enzymes presented higher enzymatic activity in the yacon peel. Based on the results obtained, it can be said that the yacon and its derivatives are important dietary carbohydrate and mineral sources and contain antinutritional substance contents lower than those harmful to health.

Stability of fructooligosaccharides, sugars and colour of yacon (Smallanthus sonchifolius) roots during blanching and drying

“…Our results report a higher POD activity than PPO as also previously reported by Pereira et al . (). However, PPO is considered as the main enzyme involved in browning due to high content of polyphenols present in vegetables.…”

“…However, some hours after treatment, a gradual browning of the yacon slices was observed from the external part of the skin towards the centre of the slices. This behaviour might be due not only to the higher content of polyphenols present in the skin but to the higher content of oxidation catalysing agents (Fe and Cu) present in the skin (Pereira et al ., ). Thus, next blanching experiments included the use of additives (chelating, acids and or salts).…”

Optimization of osmotic dehydration of yacon slices

“…The interest in this tuber has increased due to its prebiotic and hypoglycaemic properties along with its high fructan content of fructooligosaccharides (FOS) type [2][3][4] . The high water activity and the quick depolymerisation reactions of fructans that occur in the post harvest [5] , results in a very short shelf life of yacon.…”

Evaluating Strategies to Control Enzymatic Browning of Minimally Processed Yacon (Smallanthus sonchifolius)

“…One of these main inconveniences is the enzymatic or oxidative browning, which results from the polymerization of phenols catalyzed by oxidoreductases, such as polyphenol oxidases (PPO). Among PPOs, peroxidases (POD) have been found in more expressive concentration in the yacon root (Pereira et al 2013). The involvement of PODs in enzymatic browning of other plants and mushrooms have Electronic supplementary material The online version of this article (doi:10.1007/s11947-015-1558-0) contains supplementary material, which is available to authorized users.…”