Influence of California-Style Black Ripe Olive Processing on the Formation of Acrylamide

Abstract

Methods used in processing California-style black ripe olives generate acrylamide. California-style black ripe olives contain higher levels of acrylamide (409.67 ± 42.60-511.91 ± 34.08 μg kg(-1)) as compared to California-style green ripe olives (44.02 ± 3.55-105.79 ± 22.01 μg kg(-1)), Greek olives (<1.42 μg kg(-1)), and Spanish olives (not detected), indicating that the higher temperatures used to sterilize the California-style green ripe and black ripe olives are required for acrylamide formation. Preprocessing brine storage influenced the formation of acrylamide in a time-dependent manner. Acrylamide increased during the first 30 days of storage. Longer brine storage times (>30 days) result in lower acrylamide levels in the finished product. The presence of calcium ions in the preprocessing brining solution results in higher levels of acrylamide in finished products. Air oxidation during lye processing and the neutralization of olives prior to sterilization significantly increase the formation of acrylamide in the finished products. Conversely, lye-processing decreases the levels of acrylamide in the final product. These results indicate that specific steps in the California-style black ripe olive processing may be manipulated to mitigate the formation of acrylamide in finished products.

Acrylamide in Table Olives

“…This might be due to the lower number of washings resulting in less leaching of soluble solids, and thus, higher concentration of acrylamide precursor(s) in olives treated by M1. Adapted from Charoenprasert and Mitchell [6]. However, contrary to the expectations, Hojiblanca olives treated by M3 behaved differently, showing higher acrylamide contents than those treated by M2.…”

“…Without heating, the formation of acrylamide in olive pulp is negligible (≈50 μg/kg) [6] or even undetectable [5]. Without heating, the formation of acrylamide in olive pulp is negligible (≈50 μg/kg) [6] or even undetectable [5].…”

“…Charoenprasert and Mitchell [6] monitored acrylamide formation in olives stored in brine over 8 months and then processed into California-style black ripe olives. Charoenprasert and Mitchell [6] monitored acrylamide formation in olives stored in brine over 8 months and then processed into California-style black ripe olives.…”

“…The formation of acrylamide was believed to be generally associated with the application of harsh heat treatment, for example, roasting, baking, and deep-frying, with temperatures exceeding 150 °C. Subsequently, different surveys on acrylamide levels in different types of table olive samples have been published [4][5][6]. Roach et al [2] were the first to report high acrylamide levels around 2000 μg/kg in samples of black ripe olives.…”

“…This type of table olives was then ranked among the top 20 and top 8 foods by mean acrylamide intake (μg/kg of body weight/day) and per portion, respectively [3]. Compared to California-style black ripe olives, the production of California-style green ripe olives as well as their acrylamide levels are relatively low [6]. The latter provided evidence that acrylamide is only detected in California-style black ripe and California-style green ripe olives, while it is not detected in other processing types such as Spanish-style and Greek-style olives.…”