Hydrolysis of fats and oils with moist oat caryopses

Abstract

To improve the economic feasibility of hydrolyzing fats and oils with moist oat caryopses, various factors affecting the efficiency of the process were studied. Caryopses produced with an impact‐type dehuller exhibited greater lipase activity than those produced by a wringer‐type dehuller. Abrasion of oat caryopses against each other in a fluidized bed released particles rich in lipase. Such lipase concentrates could be added to moist caryopsis reactors to speed fat hydrolysis. Beef tallow, lard, soybean oil and crambe oil were hydrolyzed more efficiently than corn oil, castor oil and milk fat. The poor hydrolysis of castor oil was attributed to the formation of esters with the hydroxy group of ricinoleic acid, and the hydrolysis of castor oil was increased by dilution of the substrate with hexane. Diglycerides inhibited the hydrolysis and accounted for the slower hydrolysis of corn oil. Hydrolysis of milk fat by moist oat caryopses resulted in preferential hydrolysis of C6 to C10 acids. Erucic acid was released from crambe oil at significantly slower rates than the other acyl groups. High conversions of fats and oils to free fatty acids could be attained by (i) exposing the fats and oils to two to three lots of moist caryopses, (ii) the use of special oat varieties with elevated lipase content, (iii) the addition of oat lipase concentrates to moist caryopsis reactors, and (iv) dilution of the substrate with hexane. Estimates of the cost of producing free fatty acids with these processes indicated that the first three should be profitable. Growth ofClostridium sporogenes spores could not be demonstrated in caryopsis reactors. During the incubation of moist oat caryopses immersed in oil, the free fatty acid content of the internal caryopsis lipid increased only slightly, but there were changes in its fatty acid composition.

Specificity of Carica papaya Latex as Biocatalyst in the Esterification of Fatty Acids with 1-Butanol

“…Various sources of lipases from plant tissues, techniques for their isolation and purification, and their properties are well documented (Mukherjee, 1994;Mukherjee and Hills, 1994). Several publications have appeared in recent years on the possible applications of lipases from plants in biotransformations of fats and other lipids (Kadyrova et al, 1983;Hassanien and Mukherjee, 1986;Piazza et al, 1989;Hills and Mukherjee, 1990;Rao et al, 1992;Ayorinde et al, 1993;Dandik et al, 1993;Ncube et al, 1993Ncube et al, , 1995Parmar and Hammond, 1994;Jachmania ´n and Mukherjee, 1996). Active preparations of lipases are relatively easy to isolate from plants (Ory et al, 1960;Hassanien and Mukherjee, 1986;Piazza et al, 1989;Rao et al, 1992;Ayorinde et al, 1993;Jachmania ´n and Mukherjee, 1996), and pronounced substrate specificities of such biocatalysts (Huang et al, 1988) can be utilized in lipid biotechnology (Mukherjee, 1990).…”

Esterification of conjugated linoleic acid by yeasts for increasing the value of plant materials

“…In processing of lipolytically active cereals, such as oats and rice, inhibition of lipases has been the major practical challenge (Liukkonen et al, 1992). In early studies on application of oat lipolytic activity, hydrolysis of vegetable oils (soybean, rice bran and corn oil), tallow and other fats has been demonstrated by moistened, ground oat seeds, oat flour, and lipase preparations from oat seeds (Parmar and Hammond, 1994;Kaur et al, 1993;Piazza, 1991).…”

“…Previously, hydrolysis of vegetable oils (soybean, rice bran and corn oil), tallow and other fats has been demonstrated by moistened, dehulled oat seeds, oat flour, and lipase preparations from oat seeds (Parmar and Hammond, 1994;Kaur et al, 1993;Piazza et al, 1992). However, the moisture contents in these experiments were considerably higher than in the present method, and the aspect of microbial safety was not addressed.…”

Continuous lipolysis reactor with a loop connecting an immobilized lipase column and an oil‐water separator

“…Many lipolysis reactors with immobilized lipase have been described (1)(2)(3)(4)(5)(6)(7)(8)(9)(10). However, no process applicable to commercial production has been reported because of two fundamental problems.…”

“…equate because the viscous oil often was suspended in the water-soluble product, and water was carried into the oil product. Loop reactors previously used for lipolysis (1,2,5,9) could not integrate the functions of continuous lipolysis, continuous separation, and continuous concentration of glycerol. Here we describe a novel loop reactor in which an immobilized lipase column and an oil-water separator are connected, allowing continuous lipolysis, good separation of oil and water, and concentration of glycerol.…”