Daphna Havkin Frenkel

Daphna Havkin Frenkel
Rutgers, The State University of New Jersey | Rutgers · Department of Plant Biology and Pathology

PhD, MBA

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46
Publications
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Publications

Publications (46)
Article
Vanillin (3‐methoxy‐4‐hydroxybenzaldehyde) is an important flavor ingredient and aroma molecule, as well as the most widely used one. Vanillin is not found in nature in its free state and, instead, accumulates as its glycoside glucovanillin in green vanilla pods (beans). The vanilla bean is not commonly used as a commercial source of pure vanillin...
Article
Full-text available
Lignin, a major component of lignocellulosic biomass, is crucial to plant growth and development but is a major impediment to efficient biomass utilization in various processes. Valorizing lignin is increasingly realized as being essential. However, rapid condensation of lignin during acidic extraction leads to the formation of recalcitrant condens...
Article
A recent publication describes an enzyme from the vanilla orchid Vanilla planifolia with the ability to convert ferulic acid directly to vanillin. The authors propose that this represents the final step in the biosynthesis of vanillin, which is then converted to its storage form, glucovanillin, by glycosylation. The existence of such a " vanillin s...
Chapter
Full-text available
This chapter is concerned with biotechnological studies on the production of vanillin. The current state of the art is analyzed, indicating some problems such as accessibility of vanillin precursors, yield, and the need for control of biosynthetic pathways. These issues are constraints on the economic production of vanillin via the biotechnology ro...
Article
Full-text available
Background Pods of the vanilla orchid (Vanilla planifolia) accumulate large amounts of the flavor compound vanillin (3-methoxy, 4-hydroxy-benzaldehyde) as a glucoside during the later stages of their development. At earlier stages, the developing seeds within the pod synthesize a novel lignin polymer, catechyl (C) lignin, in their coats. Genomic re...
Conference Paper
Full-text available
Currently, vanilla bean production worldwide is threatened by an epidemic of fungal root rot diseases that is projected to curtail supply of vanilla in coming years. Due to economic considerations pesticides to reduce losses are not generally used in production of vanilla beans. In an effort to identify defensive bacterial endophytes that might eve...
Article
Full-text available
We report the occurrence of Bacillus amyloliquefaciens in vanilla orchids (Vanilla phaeantha) and cultivated hybrid vanilla (V. planifolia × V. pompona) as a systemic bacterial endophyte. We determined with light microscopy and isolations that tissues of V. phaeantha and the cultivated hybrid were infected by a bacterial endophyte and that shoot me...
Data
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Abstract for Bakto Flavor conference on Vanilla to be held November 5-6, 2013. Shoot apex bacterial biofilms in a cultivated hybrid variety of vanilla orchid (Vanilla pompona x V. planifolia) fix atmospheric nitrogen and fixed nitrogen flows into tissues of the shoot apex, from where it is transported into older tissues. Both V. planifolia and V....
Data
Full-text available
We hypothesize that shoot apex bacterial biofilms observed in a cultivated hybrid variety of vanilla orchid (Vanilla pompona x V. planifolia) fix atmospheric nitrogen and that some of the fixed nitrogen escapes from biofilms and flows into tissues of the shoot apex, from where it is transported into older tissues. The vase-like ensheathing structur...
Article
Full-text available
Lignins are complex phenylpropanoid polymers mostly associated with plant secondary cell walls. Lignins arise primarily via oxidative polymerization of the three monolignols, p-coumaryl, coniferyl, and sinapyl alcohols. Of the two hydroxycinnamyl alcohols that represent incompletely methylated biosynthetic products (and are not usually considered t...
Article
Full-text available
Wound healing is a dynamic and complex process affected by tissue hydration, the presence of bacteria, inflammation, and other variables. Oregano has potent antibacterial, antifungal, antioxidant, and anti-inflammatory properties. Studies of oregano ointment on wound healing are lacking. To determine the efficacy of 3% oregano extract ointment on w...
Article
Full-text available
Caffeoyl CoA O-methyltransferases (OMTs) have been characterized from numerous plant species and have been demonstrated to be involved in lignin biosynthesis. Higher plant species are known to have additional caffeoyl CoA OMT-like genes, which have not been well characterized. Here, we identified two new caffeoyl CoA OMT-like genes by screening a c...
Article
Full-text available
Purpose of review: Herbs contain a volatile fraction containing essential oils and a non-volatile fraction containing compounds with biological activity, including antioxidant activity. However, there is an overwhelming amount of information on antioxidant activity in herbs, without knowing which fraction contributed to this activity. The purpose o...
Article
In the summer of 2005, individual plant selection was performed on different oregano populations started at Applied Plant Research (PPO-WUR) in Lelystad, The Netherlands. Selection was focused on erect growing, healthy, leafy but flowering, productive plants. Samples of these visually selected plants were analyzed for essential oil content and its...
Chapter
Lexicon of Vanilla Aroma/Flavor DescriptorsReferences
Chapter
IntroductionBotany of the Vanilla PodOn-The-Vine Curing Process in a Vanilla PodOff-The-Vine Curing Process of Vanilla BeansActivity of Hydrolytic Enzymes Occurring in a Curing Vanilla PodActivity of Oxidative Enzymes Occurring in a Curing Vanilla PodVanilla ProductsSummary and Conclusions Addendum: Commercial Curing Methods of Green Vanilla BeanRe...
Chapter
HistoryUses of Vanilla in the IndustryMajor US Vanilla CompaniesIntroduction to the StudyMaterials and Methods Results and DiscussionConclusion and RecommendationReferences
Book
Vanilla is the world's most commonly-used flavour and fragrance, used in foods, cosmetics, pharmaceuticals and other products and is therefore of considerable economic importance. This book provides a comprehensive overview of the science and technology used in the production and supply chain of vanilla products. A wide range of international autho...
Book
Biotechnology can deliver complex flavors both as fermentation products and single constituents. Recent developments in transgenic research have spawned numerous studies in the use of metabolic engineering of biosynthetic pathways to produce high-value secondary metabolites that can enhance the flavors of food products. Biotechnology is also playin...
Chapter
Vanilla is the most popular flavor in the world, the most widely used on both a dollar and tonnage basis. Natural vanilla flavor is obtained from beans of the climbing vanilla orchid, Vanilla planifolia. The annual world consumption of vanilla beans, on average, is estimated to be over 2,000 tons (Ranadive 2003, 2006). Vanilla, next to saffron is t...
Article
Vanilla is the most widely used flavour in the food and confectionery industries. It is the most well-known and familiar flavour. Worldwide annual consumption today is estimated at 1500 tons, with 1250 tons imported to the USA alone. After a crisis during 2000-2005 the estimated world consumption of vanilla was reduced by almost 50 percent (1). Fig...
Article
Full-text available
The vanilla bean, the fruit of the climbing orchid Vanilla planifolia, is used for the commercial production of vanilla flavour, consisting of vanillin and other numerous flavour compounds. Development of the prized vanilla flavour in harvested green beans is dependent, however, on a curing process. Studies on the botany of vanilla beans revealed t...
Article
Full-text available
The biosynthesis of many plant secondary compounds involves the methylation of one or more hydroxyl groups, catalyzed by O-methyltransferases (OMTs). Here, we report the characterization of two OMTs, Van OMT-2 and Van OMT-3, from the orchid Vanilla planifolia Andrews. These enzymes catalyze the methylation of a single outer hydroxyl group in substr...
Article
The final enzymatic step in the synthesis of the flavor compound vanillin (4-hydroxy-3-methoxybenzaldehyde) is believed to be methylation of 3,4-dihydroxybenzaldehyde. We have isolated and functionally characterized a cDNA that encodes a multifunctional methyltransferase from Vanilla planifolia tissue cultures that can catalyze the conversion of 3,...
Article
Full-text available
The fruit of the climbing orchid Vanilla planifolia (vanilla bean) is used for the commercial production of the prized vanilla flavor, consisting of vanillin and other numerous flavor compounds, with the use of a curing process. However, present curing methods yield only a fraction of the vanilla flavor from flavor precursors in green beans. Studie...
Article
A unique secretory tissue produces the most important flavoring agent. Vanillin accumulates in the secretion around the seeds in the mature fruit of the vanilla orchid. A unique secretory tissue that is composed of closely packed unicellular hairs is located in the three gaps between the placentas along the central fruit cavity. These cells contain...
Article
Tissue cultures of the vanilla orchid, Vanilla planifolia, produce the flavor compound vanillin (4-hydroxy-3-methoxybenzaldehyde) and vanillin precursors such as 4-hydroxybenzaldehyde. A constitutively expressed enzyme activity catalyzing chain shortening of a hydroxycinnamic acid, believed to be the first reaction specific for formation of vanilla...
Chapter
Vanilla extract is widely used in the food and the confectionery industry. Vanillin is the most abundant component of vanilla extract. An understanding of the biosynthetic pathway of vanillin may be important for regulating the production of the compound in plants. It is agreed that vanillin (C6-C1) is a product of phenylpropanoid (C6-C3) compounds...
Article
Combining biochemistry with genetic engineering can increase the yield of natural ingredients and improve the economics of tissue culture.
Chapter
Vanilla is the most widely used flavor in the food and confectionery industries. Worldwide annual consumption was 1900 tons in 1995, with 1400 tons imported to the USA alone. Vanilla flavor is extracted from the cured bean of Vanilla planifolia, a member of the orchid family originated in Mexico. A small amount of beans is produced from yet another...
Article
A cluster culture of Vanilla planifolia Andr. has been established from shoots. It has been maintained in the dark. Various light conditions had little effect on its growth. However, the light conditions did affect the production in both quantity and quality of compounds associated with the vanillin pathway, particularly the 4-hydroxy-3-methoxybenz...
Article
Short-term intraperitoneal administration of mirex for 4 days) to male Sprague-Dawley rats resulted in a 264 % increase in free radical activity as measured by an in vitro assay for hydroxyl radicals.
Article
Typescript. "Graduate Program in Food Science." Thesis (Ph. D.)--Rutgers University, 1982. Includes bibliographical references (leaves 136-142). Vita.

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