Role of Physical Structures in Bulk Oils on Lipid Oxidation

Abstract

Lipid oxidation is important to food manufacturers especially when they increase unsaturated lipids in their products to improve nutritional profiles. Unfortunately, the number of antioxidants available to food manufacturers to control oxidative rancidity is limited and the approval of new antioxidants is unlikely due to economic barriers in obtaining government approval for new food additives. Therefore, new antioxidant technologies are needed for food oils. This paper reviews the current knowledge of lipid oxidation in foods with emphasis on how physical properties of food systems impact oxidation chemistry. In particular, the role of association colloids in bulk oils on lipid oxidation chemistry is discussed in an attempt to understand mechanisms of oxidation. Increasing the understanding of how physical properties impact lipid oxidation could lead to the development of novel antioxidant technologies that not only protect the oil against oxidation and increase shelf-life but also allow food manufacturers to include more nutritionally beneficial fatty acids in their products.

Farelo integral de arroz parboilizado submetido a armazenamento prolongado para alimentação de codornas de corte

“…Essa diferença pode ter sido resultante dos efeitos dos processos de hidrólise e oxidação lipídica durante o armazenamento, conforme mostrado com o aumento dos índices de acidez e peróxidos. Esse resultado corrobora os obtidos por Chaiyasit et al (2007), que afirmaram que a lipoperoxidação diminui o valor energético do alimento, em decorrência da destruição dos ácidos graxos. Mujahid et al (2003) relataram menores valores de digestibilidade da gordura com o tempo de armazenamento do farelo de arroz; no entanto, a magnitude desse efeito depende do nível de inclusão e do processamento térmico ao qual o farelo foi submetido.…”

Capacidade antioxidante total de óleos vegetais comestíveis: determinantes químicos e sua relação com a qualidade dos óleos

“…Além de apresentarem bioatividade no organismo humano, os antioxidantes naturais protegem os óleos vegetais contra a ação de radicais livres que iniciam e perpetuam a peroxidação lipídica, que consiste na principal forma de degradação dos óleos vegetais e em importante fonte de prejuízos para a indústria de alimentos 3 . Dessa forma, os antioxidantes naturais presentes nos óleos vegetais têm sido foco de interesse científico e tecnológico nas áreas de ciência de alimentos e nutrição, a partir de duas abordagens principais: promoção de maior estabilidade oxidativa dos óleos e bioatividade no organismo humano.…”

The effect of antioxidants on quantitative changes of lysine and methionine in linoleic acid emulsions at different pH conditions

“…It was found that polar antioxidants (e.g. ascorbic acid, carnosic acid, and rosmarinic acid) are the most effective in bulk oils, due to their accumulation at the air-oil interface or in reverse micelles within the oil where lipid oxidation reactions occur (Chaiyasit et al, 2007;Heins et al, 2007;McClements and Decker, 2000). The higher efficiency of nonpolar antioxidants in emulsions is a result of their concentration at the interface between the lipid and the polar phase, so that the antioxidant is ideally located to protect the lipids from radicals generated in the aqueous phase.…”