CUBING CHARACTERISTICS OF FRACTIONATED SUN-CURED AND DEHYDRATED ALFALFA CHOPS

Abstract

A single cubing unit was designed and constructed to study the cubing characteristics of fractionated sun-curedand dehydrated alfalfa chops. The moisture content of dehydrated and sun-cured chops were 6% and 7% (wet basis),respectively. A forage particle separator was used to separate leaf and stem fractions. The leaf and stem fractions werecombined to get five different samples each for sun-cured and dehydrated alfalfa with leaf content ranging from 0 to 100%in increments of 25%. A hydraulic cubing machine with a maximum capacity of 14.0 MPa was used to apply compressivepressures on the chops. The effect of chop moisture content (6%, 10%, and 14%), leaf content (0, 25%, 50%, 75%, and 100%),chop preheat temperature (50.C, 75.C, and 100.C), cube die temperature (75.C, 90.C, 150.C, and 200.C), applied pressure(2.5, 5.0, 7.5, 9.0, 10.0, 12.0, and 14.0 MPa) and chop residence time in the cubing unit (10, 12, 15, and 30 s) on cube qualitywas studied. Cube quality was assessed based on its density, color, long fiber content, durability and hardness. Results weresubjected to statistical analysis to determine the effect of the processing and material variables on cube quality. The densityof dehydrated and sun-cured cubes increased with an increase in pressure, residence time, leaf content and cube dietemperature. Cube hardness increased with an increase in pressure and residence time. Cube durability increased with anincrease in pressure, residence time, and die temperature. Change in leaf content had an insignificant effect on cubedurability, except for dehydrated alfalfa at 50% leaf content and sun-cured alfalfa at 100% leaf content. Cube greennessdecreased with a decrease in leaf content and residence time, however, greenness increased with an increase in dietemperature.