A highly active esterase from Lactobacillus helveticus hydrolyzes chlorogenic acid in sunflower meal to prevent chlorogenic acid induced greening in sunflower protein isolates.

Chlorogenic acid (CGA) is an ester between caffeic and quinic acid. It is found in many foods and reacts with free amino groups in proteins at alkaline pH, leading to the formation of an undesirable green pigment in sunflower seed-derived ingredients. This paper presents the biochemical characterization and application of a highly active chlorogenic acid esterase from Lactobacillus helveticus. The enzyme is one of the most active CGA esterases known to date with a Km of 0.090 mM and a kcat of 82.1 s-1. The CGA esterase is easily expressed recombinantly in E. coli in large yields and is stable over a wide range of pH and temperatures. We characterized CGA esterase's kinetic properties in sunflower meal and demonstrated that the enzyme completely hydrolyzes CGA in the meal. Finally, we showed that CGA esterase treatment of sunflower seed meal enables the production of pale brown sunflower protein isolates using alkaline extraction. This work will allow for more widespread use of sunflower-derived products in applications where neutrally-colored food products are desired.

"Let's Talk about the Institution": Same-Sex Common-Law Partners Negotiating Marriage Equality and Relationship Legitimacy.

The 2005 Canada-wide legalization of same-sex marriage provided same-sex couples with access to an institution they had previous been excluded from. Yet not all couples choose to marry. In this paper, we examine why this is the case, considering the role of personal, political, and historical factors. We draw on 22 interviews with people in common-law same-sex relationships in Toronto to examine how they understand their relationship within the new context of marriage equality. We find that participants feel they are held accountable to marriage as a default relationship legitimacy norm, indicating that this new institutional access is accompanied by a set of social expectations. Despite their awareness of the need to navigate a social context favoring marriage, participants individualize their relationship decisions as personal rather than political. Participants often contradict themselves as they articulate what marriage means to them, suggesting that, in this period of legal and social transition, people are negotiating multiple meanings, societal messages, and traditions when it comes to making sense of their relationship. We discuss the implications of these findings for LGBQ activism and the framing of sexuality-based inequalities in Canadian society.