Page 22 - Summer 2019 Journal

HYDROLYSIS VERSUS OXIDATION
As we have seen from the above discussion, “oxidation” refers to
the breakdown of fatty acids into toxic components like aldehydes and ketones. This is not the same as hydrolysis, which refers to the chemical breakdown of triglycerides into individual free fatty acids and glycerol.
Hydrolysis of triglycerides is what happens during digestion. When we eat fats, our bodies produce bile, which breaks down the triglycerides into individual or “free” fatty acids. Since fermentation is basically a di- gestive process, we can expect to find a lot of free fatty acids in fermented fish products like fermented cod liver oil.
Triglycerides are composed of three fatty acids joined to a glycerol molecule, which is the way fats occur in nature. Typically, the middle fatty acid is the most unsaturated of the three, that is, the most vulner- able to oxidation. When a triglyceride is hydrolyzed into individual fatty acids, the middle fatty acid no longer has the protection of the other fatty acids on either side of it. The fish oil industry claims that the presence of free fatty acids in a fish oil is a sign of rancidity, but it is only the sign of potential rancidity. If the free fatty acids in the product are protected in some way, there will be no oxidation after hydrolysis.
In a fermentation process that involves no heat, and in which oxygen is removed from the product by lactic acid bacteria, the free fatty acids will be largely protected from oxidation.
Since this protection is absent in most fish oils, the oil refining in- dustry removes the free fatty acids by treating the oil with caustic soda (sodium hydroxide), which converts the free fatty acids into insoluble soaps. After a reaction time of around thirty minutes, with slow stirring and a temperature of around 170 degrees F (hot enough to affect adversely the omega-3 fatty acids still bound as triglycerides), the industry then uses centrifugation to eliminate the water fraction and washes the oil with water to remove the remaining soap.
In addition to the protective environment afforded by lactic acid bacteria, a number of antioxidants are formed or released during the fermentation process. For example, polyphenols are natural antioxidants that occur in seaweeds and other marine algae. Levels of polyphenols in marine algae can reach up to 20 percent of dry mass.5 Studies have noted a linear relationship between the polyphenolic content of seaweed
FIGURE 1: Catechol and Catechin
products and their antioxidant capacity, mean- ing that antioxidant capacity strengthens as polyphenolic content increases.6
While fish do not produce polyphenols directly, marine fish such as shad and other small schooling fish eat algae. Cod is an “apex predator,” feeding on other fish, including algae- eaters, and so cod accumulates polyphenols in its flesh and oil.
Of the many different polyphenols found in algae, catechol and catechin (Figure 1) are found in nearly all species.
Catechol and catechin exert their anti- oxidant activity by trapping peroxyl radicals, which perpetuate lipid oxidation.7 The resulting compact structure, called an ortho-quinone, puts oxygen into a non-reactive double bond, thus halting destructive free radical chain reactions and giving stability to the oil.
ORAC SCORES
Oxygen radical absorbance capacity
(ORAC) is a method of measuring antioxidant, including polyphenol, levels in foods. Since 2012, the USDA has not allowed food companies to list ORAC levels in their products because there is no proof that the compounds producing the ORAC score have any physiological effect once consumed.
While it is true that the dietary polyphenols measured in the ORAC test are poorly con-
TABLE 1. ORAC scores for fermented cod liver oil, other cod liver oils and other high-antioxidant foods
Food ORAC Score
(In Trolox equiv., μmol per 100g)
Extra Virgin Olive Oil 372 Carrots, Baby Raw 436
Tea Brewed 1128
Red Grape Juice 1788 Nuts, Almonds 4454
Raw Blueberries 4669 Fermented Cod Liver Oil* 4333-7494 Brand A Cod Liver Oil* 221
Brand B Cod Liver Oil* 2838 Brand C Cod Liver Oil* 404 Brand D Cod Liver Oil* 993
*University of Nebraska test data.
20 Wise Traditions
SUMMER 2019