MORPHOLOGICAL, PHYSICAL, ORGANOLEPTIC, CHEMICAL AND FUNCTIONAL CHARACTERIZATION OF NATIVE POTATOES (Atena Editora)

Abstract

The present investigation began with the morphological characterization, describing the general shape of the tubers, depth of the "eyes", predominant and secondary color of the skin and pulp of 24 varieties of native potatoes. Most presented round shapes (10 ecotypes); "eyes" with medium depth (14 ecotypes); yellow skin without secondary color (8 ecotypes) and light yellow flesh (9 ecotypes). Regarding size, in general it was possible to observe that the native ecotypes presented heterogeneous tubers in size and weight (between 20 g and greater than 90 g).

In the physical characterization, it was found that the maximum value of specific gravity of 1.11 corresponds to the Chaucha Amarilla and Calvache varieties; They are followed by the varieties Sta. Rosa, Coneja Blanca, Violeta, with an average value of 1.10.

Regarding the cooking time, the tubers, which presented texture values ​​greater than 10 kgf, and a weight greater than 90 g, required cooking times greater than 40 min. Tubers weighing between 20 and 80 g, and texture values ​​between 7 and 9 kgf, required cooking times of less than 30 min. to achieve the appropriate texture for consumption.

The Chaucha Amarilla, Chaucha Holandesa, Yema de Huevo and Sta. Rosa varieties began the sprouting process in the first week of storage, while the Chivolulo, Moronga and Tushpa varieties sprouted from the ninth week.

From the sensory analysis it can be deduced that the varieties that the panelists liked the most were those with yellow skin and pulp colors.

The native varieties, which reached a good level of acceptability in the attributes: size, shape, skin color, pulp, and those with unusual morphological characteristics in shape, skin color, and pulp, were subjected to chemical analysis.

The highest dry matter content corresponded to

the Coneja Blanca variety (27.32%), fiber from Chaucha Holandesa (6.07%), fat from the Quillu variety (0.68%), protein from the Sta. Rosa variety (10.62%), and starch to the Ovaleña variety (87.49 %). Regarding the mineral content, the native varieties are rich in iron (16.47 mg / 100 g, Black Rabbit) and potassium (2103.33 mg / 100 g, Dutch Chaucha).

The starch of the Chaucha Amarilla variety showed the highest amylose content (36.81 %), the maximum viscosity of the Puña variety (2070 UB) and the highest gelling index of the Sta. Rosa variety (430.00 UB). The photographs of the starches revealed their oval shape; the granules presented a maximum and minimum average diameter (microns) of 50.42; 30.37; 26.34 and 18.23 μm, for the Puña and Chaucha Holandesa varieties, respectively.

The functional characterization was carried out in the varieties of pulp and/or peel of purple, red and intense yellow colors, and with a higher level of acceptability among consumers.According to the recommended daily dietary allowance of vitamin C (50 mg/100 g) (8), native potatoes could contribute to the daily requirement, from 15% (7.67 mg/100 g, Calvache) to 50% ( 26.22 mg / 100 g, Uvilla).

From the results obtained for the carotene content, the highest values ​​correspond to the Chaucha Amarilla variety (11.38 ug/g of sample), with an intense yellow flesh, followed by the Quillu variety (10.03 ug/g of sample).

The Tushpa, Dolores and Macholulo varieties presented the highest values ​​of polyphenols (646.33 - 516.25 - 518.59 mg gallic acid /100 g), the same ones that correlate with the highest concentration of anthocyanins.