Physico-chemical properties of selected Irish potato varieties grown in Kenya

Abstract

Potatoes have attracted great interest as a feasible solution to food insecurity and climate change in Kenya. Many varieties have been developed but their nutritional value and suitability for domestic and industrial use are not sufficiently studied. A comparative study of physical attributes (tuber weight, size, shape, eye depth and number, specific gravity, colour) and nutrient composition (proximate, minerals, vitamins, and simple sugars) of three varieties (Unica, Shangi and Dutch robjin) were evaluated using standard methods. Shangi and Unica had lengths above 50 mm recommended for French fry processing, but had deep eyes (1.54-2.98 mm). Unica had a red skin colour while Shangi was yellow. Both varieties had yellow coloured flesh. The specific gravity of the varieties ranged from 1.08-1.12. Shangi and Unica were suitable for processing based on their physical attributes except for eye-depths. Dutch robjin had the highest content of protein (1.76%), carbohydrates (20.43%), total ash (1.10%), crude fibre (1.11%), iron (0.87 mg/100 g), thiamine (0.036 mg/100 g), niacin (0.93 mg/100 g), pyridoxine (1.92 mg/100 g) and folic acid (34.62 µg/100 g). Unica had the highest zinc (0.41 mg/100 g) and calcium (8.51 mg/100 g) contents. Reducing sugar content across the three varieties was within recommended range for processing (97.75-107.53 mg/100 g). There was a significant (p<0.05) varietal difference in most of the nutrient components. Dutch Robjin showed the best nutritional quality.

Effect of Pretreatments and Drying Methods on Physical and Microstructural Properties of Potato Flour

“…The Dutch Robjin variety had more eyes as compared to the other varieties. The more eyes the tuber has, and the deeper they are, the greater the peeling loss [ 45 ].…”

“…On the other hand, the Dutch Robjin resulted in the highest flour yield in all the processing conditions. This might be attributed to its high specific gravity and dry matter compared to the other varieties [ 34 , 36 , 45 ]. There was no significant difference in yields of the flour obtained from oven drying and freeze-drying.…”

Effect of nutrient solution concentrations on the growth and yield of potato (Solanum tuberosum L.) varieties grown from apical rooted cutting in a hydroponic system

“…Minitubers weight classes were graded according to Gbollie et al (2022); C1 (class 1, <8g), C2 (Class 2, 8.01-15.99g), C3 (Class 3, 16-18.00g) and C4 (Class 4, >18g). Tuber weight (g) of individual plants was measured using an electronic weighing balance after harvest as described by Gikundi et al (2021) and used to calculate total yield per hectare using the formula below:…”