Method for Electron Microscopic Examination of Heated Whey and Ultrafiltrate Systems

Abstract
Whey prepared from raw skimmilk by centrifugation at 147,000 g-2 hr. (UC whey) or acidification to pH 4.6 and recentrifugation as above (A-UC whey) were heated at 80[degree]C for various times. Ultrafiltrate prepared from raw skimmilk was heated in a boiling bath for 30 min. Electron microscopic examination revealed that heating ultrafiltrate results in needle-shaped as well as cubic-shaped crystalline particles. Heated A-UC whey contained large, irregularly-shaped masses of material of up to about 10 [mu] in diameter. The protein aggregates in heated UC whey appeared as clusters of smaller, spherically-shaped particles.