A modified method for the determination of monoglyceride in fats and oils by oxidation with periodic acid

Abstract

SummaryThe original periodic acid method of Pohleet al. has been modified to render it more suitable for routine control purposes. An attempt was made to minimize the danger of obtaining high estimates when assaying commercial concentrates prepared from mixed glycerides containing C18 saturated and unsaturated fatty acids. The sharpness of the titration endpoint was markedly improved.

Food Coatings, Permeability of Acetostearin Products to Water Vapor

“…The products were further purified by bleaching with neutral, activated clay and then mild deodorization or steam distillation at low pressure. The finished products were analyzed for melting range, monoglvceride content (5), and hydroxyl value. The latter was determined according to the acetylation method of West et al (13), modified by using 1 part of acetic anhydride to 3 parts of pyridine.…”

“…Strain (7) in an investigation of the leaves of some 50 dif-ferent species of plants, observed the following xanthophylls in each: lutein, violaxanthin, neoxanthin, zeaxanthin, and cryptoxanthinlike pigments. Karrer et al (5) were unable to confirm the presence of neoxanthin and zeaxanthin in fresh leaves and stated that leaves contain only two principal xanthophylls which they called xanthophyll (lutein) and xanthophyllepoxide (violaxanthin). More recently, Moster, Quackenbush, and Porter (6), working with corn seedlings, confirmed the presence of neoxanthin and zeaxanthin in fresh leaf material.…”

Enzymatic preparation of monoglycerides in microemulsion

“…To a 20-ml sample of the chloroform solution was added 0.050 ml 70% perchloric acid in order to induce acyl group migration (8). After 90 seconds stirring 50 ml periodic acid was added and analysis for vicinal diol was carried out as described in the literature (9,10). In the calculation of total monoglyceride a correction factor of 1.15, suggested in the literature (8,11), was used.…”

Physical properties of aceto‐ and butyro‐oleins, mono‐olein, and diolein

“…Purified methyl oleate derived from pecan oil was interesterified with glycerol, the mixed glycerides were fractionated by molecular distillation, and the mono-olein fraction was further purified by crystallization from acetone. Purity of the final product was 98.6%, as analyzed by the periodic acid method of Handschumaker and Linteris (12). The 1,3-diolein was prepared by repeatedly crystallizing from acetone the diolein fraction obtained as a by-product in the purification of the 1-mono-olein by molecular distillation.…”

“…As a check on purity all of the compounds were analyzed for monoglyceride content (12) and hydroxyl value. The latter analysis was made according to the procedure of West et al (20) except that the weight ratio of the acetic anhydride to pyridine employed was 1:4.…”