Hydrolytic Rancidity in Milk. I. Surface Tension and Fat Acidity as Measures of Rancidity

Development of Rancidity in Walnuts

The rancidification of walnuts was promoted by storing shelled kernels at 38°C for 4 weeks. Of six varieties tested, only 'Howard' and 'Chandler' kernels went rancid during this period. Their deterioration was preceded by the appearance of lipase (an oil digesting enzyme) in kernels and an accumulation of free fatty acids in the oil. The implications and limitations of these observations are di...

Rancidity in Indian butterfats (ghee).

It has long been realized that the analytical characteristics of deteriorated butterfats depart considerably from those of the fresh fats. It is the more surprising, therefore, that the changes in butterfat, or ghee, during ordinary rancidificationin loosely corked containers exposed to diffused daylight-have not been more intensively studied. Elsdon, Taylor & Smith (1931) studied commercial bu...

Relationship Between Hydrolytic Rancidity, Oil Concentration, and Esterase Activity in Rice Bran

Cereal Chem. 80(6):689–692 Hydrolytic rancidity restricts the utilization of rice bran, reducing its potential value. In the present study, three groups of eight rice cultivars each displaying different levels of oil concentration (high, medium, and low) were cultivated in 1999 and 2000 under field conditions and evaluated for oil content, hydrolytic rancidity, and esterase activity in the bran...

Milk-Fat Surface Tension and Surfactant Interactions

Xiv. the Rancidity of Coconut Oil Produced by Mould

IT is now generally agreed that the deterioration of oils and fats, whether due to the action of air, light and moisture, or to the action of micro-organisms, is an oxidative process subsequent to partial hydrolysis. In these two forms of rancidity-that of pure fats (where the absence of nidus prevents bacterial or mould growth) and that caused by micro-organisms-the course of the oxidation is ...