DIAGNOSTICS OF TECHNICAL MATURITY OF SUGAR CORN
KOLTUNOV Victor,
Doctor of Agricultural Science, Professor of KyivNational University of Trade and Economics
KOVAL Аlyna,
Postgraduate of Kyiv National University of Trade and Economics
ROMANENKO Roman,
Candidate of Technical Sciences, Associate Professor of Kyiv National University of Trade and Economics
DIAGNOSTICS OF TECHNICAL MATURITY OF SUGAR CORN
Background. The duration and onset phase of technical maturity of сorn in different soil and climatic zones are not the same and depend on weather conditions during flowering and grain ripening [1]. According to the "Guide of product’s storage" sugar corn of technical stage of ripeness must have developed corncob and dense green wrapper, yellow corn, high (at least 65–70 %), grain yield, sugar content 3–5 %, delicate texture, pleasant taste and flavor. Recommended storage time at 0 °C is 4–8 days. [10]
The aim of the study is to determine the technical parameters of the stage of sugar corn ripeness for structural and mechanical properties, chemical composition and organoleptic evaluation of grains in different parts of corncob.
Material and methods. Measuring the strength of grain was held in the lower, middle and upper parts of the corncob. Determination of the resistance was carried out by means of the torque sensor with measurement range 1×103÷5 Н. General dry matter was determined gravimetrically after drying the sample to constant weight at 100–105 °С. Tasting examination of the boiled sugar corn was conducted by the developed five- point scale.
Results. The smallest resistance of the grains located on top of a corncob is about 2005 mN, on the second place – the grain of the lower part of a corncob (2150 mN). The highest resistance to indicator’s power is defined in corn’s grain located in the middle of the corncob – 2428 mN. The calculated values of the strength limits correlate with total solids content of corn (table 2) and tasting score of the cooked corncobs (table 3). By analyzing the obtained data array the lower and upper threshold is defined – 1150 and 4000 kN / m2 respectively.
Conclusion. Optimal strength limits (upper and lower) of the corn grains in different parts of the corncob, in which it is advisable to decide of the time of harvest are defined. In order to simplify the definition of technical stage of ripeness of sugar corn in the field it is recommended to make measurements of the grain resistance only in the middle of the corncob, and its calculated strength limits must be in the range of 300–4000 kN / m2.
Keywords: structural and mechanical properties, indenter, torque sensor, sweet corn, corncob.
FREE FULL TEXT (PDF)