Endotoxin Content and Fiber Properties of Raw Cotton

Abstract

The content of endotoxin was determined for 255 samples of 1979 crop, American upland raw cotton derived from seven grade divisions and five color groups. A bale of raw cotton from the better white grades contained less than one gram ofendotoxin, whereas tinged and yellow stained cottons were found to have five or more grams of this microbial material. Fiber yellowness was significantly and positively correlated with endotoxin content of representative raw cottons from the Southwest. By contrast, the endotoxin content of representative cottons from all other major geographical regions was significantly and inversely correlated with fiber maturity. For the 1979 crop there was an absence of significant differences in endotoxin levels among representative sample groups from five major U.S.A. growing regions..

Variation of Microbial Contaminants in Classers' Raw Cottons

“…A similar trend was found among 1979 raw cottons, but the number of samples (as low as 14 per region) examined was too meager to elicit statistical differences [ 10].…”

“…Unfortunately, we could not say that this is a consistent relationship because for the previously studied 1978 and 1979 crops, grayness values were obtained with the HVI [ 14] and as such are not directly relatable to grayness values of the 1980 crop where an unmodified Nickerson-Hunter cotton colorimeter was used [ 13]. In past studies we found an inverse and significant relationship between micronaire values and endotoxin levels of raw cotton [4,10]. A similar relationship was found here for the 1980 crop (Table II).…”

“…A number of grading parameters including micronaire, maturity, fineness, upper half mean (UHM) length, length uniformity, strength, and yellowness were found to be related significantly to raw cotton endotoxin levels [ 10]. Significant differences between endotoxin level of raw cottons from separate geographical regions were not found but the number of .…”

“…In previous studies we indicated that classers' samples of raw cotton contained amounts of endotoxin varying from 0.08 to about 500 ng per mg of lint [4,10]. A number of grading parameters including micronaire, maturity, fineness, upper half mean (UHM) length, length uniformity, strength, and yellowness were found to be related significantly to raw cotton endotoxin levels [ 10].…”

“…In April 1981, all samples were analyzed for fiber maturity (maturity ratio, proportion of mature fibers and causticaire maturity) and fineness (fineness in millitex and denier) using the IIC Shirley fineness/maturity tester at Cotton Incorporated. With the exception of fiber grayness and yellowness, descriptions of the aforementioned physical parameters are found in earlier publications [4,10]. The HVI at the Texas Textile Research Center measured grayness and yellowness using the Nickerson-Hunter cotton colorimeter in a somewhat different manner than that used previously.…”