Enzyme-aided extractions

In all these approaches, the enzymes are used to break the cell walls of the oil-bearing material and release the oil. The structure of a cell wall is quite complex and in some cases made up of various strata. In plants where enzyme-aided extractions have been mostly practised, the cell walls are generally made up of compounds such as pectic substances. 

Ramadan, M. F., Sitohy, M. Z., and Moersel, J.-T. (2008). Solvent and enzyme-aided aqueous extraction of goldenberry (Physalis peruviana L.) pomace oil impact of processing on composition and quality of oil and meal. Eur. Food Res. Technol. 226, 1445-1458. 

The term fermentation was obtained from the Latin verb fervere which describes the action of yeast or malt on sugar or fruit extracts and grain. The boiling is due to the production of carbon dioxide bubbles from the aqueous phase under the anaerobic catabolism of carbohydrates in the fermentation media. The art of fermentation is defined as the chemical transformation of organic compounds with the aid of enzymes. The ability of yeast to make alcohol was known to the Babylonians and Sumerians before 6000 bc. The Egyptians discovered the generation of carbon dioxide by brewer s yeast in the preparation... 

It is important to identify and measure the concentrations of a number of compounds in a mixture simultaneously for several reasons. First, among related compounds there may exist precursors of active ones, and pathways of pheromone synthesis may be elucidated. This is true for steroids in the human axilla. Nixon etal. (1988) determined the concentration of five steroids extracted from axillary hair of adult men aged 18 to 40 years. The relationships in concentrations between the two ketones 5Q -androst-16-en-3-one and 4,16-androstadien-3-one suggest that axillary bacteria reduce the former to the latter with the aid of the enzyme 4-ene-5a-reductase. Humans have a low olfactory threshold for several 16-androstenes, and the fact that some men have large quantities of 16-androstenes (Nixon etal., 1988) is biologically suggestive. 

Ranalli, A., Malfatti, A. and Cabras, P. (2001) Composition and quality of pressed virgin olive oils extracted with a new enzyme processing aid. J. Food Sci., 66, 592-603. 

Not all MIPS enzymes from thermophiles may have divalent metal ion-dependent activities. While crude protein extracts of A. fulgidus exhibited a MIPS activity that absolutely required divalent metal ions and was totally inhibited by 1 mM EDTA, the production of I-l-P from G-6-P (carried out >75 °C) by protein extracts from M. igneus and T. maritima was observed in the presence of 1 mM EDTA. This observation (Chen and Roberts, unpublished results) suggests that either the MIPS from these particular archaea is not divalent metal ion-dependent or that the metal ions bind very tightly and are not easily removed. None of the MIPS activities from thermophiles are affected by the addition ofNELt-1". Since the divalent cation in A. fulgidus MIPS has been suggested to aid in the aldol condensation and since this is supposedly done by NH4+ in the yeast enzyme, it is of interest how this step occurs in the other archaea and bacteria. 

Because the enzyme extracts were made from acetone-dried powders, they were free of all nucleotides (40, 42). This strategy confined the dissimilation of labeled Rib 5-P to a hexose 6-P end point. Glc 6-P could not recycle, and the labeled prediction pattern was not scrambled. Mg + was also omitted from the reaction mixture to inhibit the activity of Fructose bisphosphatase (EC 3.1.3.11) and production of a contaminating Fru 6-P from Fru 1,6-P2 formed by aldolase and the triose-P products of the TK reactions. It is curious that Fru 1,6-P2, which is an Aid product, was formed (Fig. 3) by the hver and pea tissue reaction mixtures but was omitted from the final construction of the scheme for Fig. 2. 

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