The Curing Process: Traditional, Short and Effective and Post-Harvest Handling of Cured Vanilla Beans
Dr. Chaim Frenkel
Rutgers University - the State University of New Jersey
New Brunswick, NJ
The objective for the curing of mature vanilla pods is two-fold: to bring out the prized vanilla flavor and to lend shelf life to cured beans. The traditional curing process consists of the following: 1. Killing by hot water scalding, freezing of wounding of the mature vanilla pod 2. Sweating by holding killed beans at high-temperature (45-50° C) and high humidity to allow enzyme-catalyzed hydrolytic release of flavor constituents from their precursors, for example, vanillin from glucovanillin 3. Sun-drying of the moist cured beans, and 4. Conditioning of cured dried bean at a moderate temperature, presumably to enhance the flavor quality. This process is prolonged, lasting up to 9 months. It is labor-intensive and is therefore expensive. Daphna Havkin-Frenkel described a quick-curing method, consisting of traditional killing or mechanical breakage of the fresh vanilla pod, followed by sweating for few days and drying of the cured beans. The process takes days, rather than months required by traditional curing. It attains characteristic flavor quality and, moreover, recovers high vanillin levels around 6-8% on dry weight basis. Recently, damaging practices has led to cured beans with inferior quality: a. Vanilla pods are harvested when reaching full size but before allowing additional time to mature on the vine to develop flavor precursors. b. Green vanilla pods are vacuum-sealed in plastic bags and held for an opportune time for curing. These anaerobic conditions lead to aberrant cellular metabolism, deficiency in flavor precursors and often off-flavor in cured beans. The industry is looking for alternatives to overcome poor quality and high cost of cured vanilla beans, a trend that might spell the end of vanilla, at least where growing and curing of vanilla result in poor quality and high cost.
Dr. Chaim Frenkel is a native of Israel where he obtained his B.Sc. degree, Hebrew University, Jerusalem. He earned his MS in Horticulture from the University of Massachusetts, Amherst, MA and his doctorate from Washington State University, Pullman. WA. He next went on to do postdoctoral work at Michigan State University, E. Lansing, MI.
He later accepted a position at Rutgers-the State University of New Jersey where he holds a position of a Professor.
Chaim Frenkel is interested in and carries basic studies on plant aging (and fruit ripening) processes. The focus of these studies is the query of metabolic and cellular cues that trigger the onset of aging processes in plants. He also studied various aspects of Vanilla Science and Technology.