Special Issue "Tannins"

Guest Editor
Dr. Amy B. Howell
Marucci Center for Blueberry Cranberry Research, Rutgers University, 125A Lake Oswego Rd., Chatsworth, NJ 08019, USA
E-Mail:

Dear Colleagues,

Tannins are a widely distributed group of compounds, found throughout the plant kingdom. There are two distinct types of tannins, the hydrolyzable tannins, which are polymers of ellagic or gallic acid esterified to a carbohydrate (usually glucose), and condensed tannins (proanthocyanidins), which are polymers of flavan-3-ols. Tannins can be high molecular weight, have very heterogeneous structures, and can form complexes with a number of other molecules (especially proteins and carbohydrates). All of these characteristics of tannins can influence their biological properties.

Tannins are astringent defense compounds that serve as predator feeding deterrents, and are produced by plants in times of stress, acting as antimicrobials. They may also play a role in fruit ripening and plant growth regulation. Tannins have a number of industrial uses, including dying and preserving, converting animal hides to leather, and the precipitation of proteins in wine and beer.

Historically, ingestion of tannins has been associated with anti-nutritional effects, especially on protein digestibility in ruminant animals. However, recent research on tannins has focused on their potential to positively impact human health, when consumed in the proper dosage and structural form. Tannins have demonstrated a host of potent biological activities, including bacterial anti-adhesion activity, anti-parasitic, antioxidant, anti-inflammatory and anti-proliferative activities, as well as influencing cell signaling and gut health.

This special issue of Molecules will consider submissions related to all characteristics of tannins (both hydrolyzable and condensed), including biological and chemical properties and potential human health effects.

Dr. Amy B. Howell
Guest Editor

Submission

Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. Papers will be published continuously (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website.

Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are refereed through a peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Molecules is an international peer-reviewed Open Access monthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 1400 CHF (Swiss Francs).

• tannin
• proanthocyanidin
• condensed tannin
• hydrolyzable tannin
• ellagitannin
• gallotannin
• flavan-3-ol
• polyphenol
• chemical properties
• astringency
• protein precipitation
• biological activities
• health effects

Type of the Paper: Review
Title: The Effect of Tannins in Mediterranean Ruminant Ingestive Behaviour: The Role of Oral Cavity
Authors: Elsa Lamy ^{1, 2}, Fernando Capela e Silva ^1,3, André Almeida ⁴, Ana Varela Coelho ^4,5, Elvira Sales Baptista ^1,6,7
Affiliations: ¹ ICAAM – Instituto de Ciências Agrárias e Ambientais Mediterrânicas, Universidade de Évora, Évora, Portugal
² ESHTE – Escola Superior de Hotelaria e Turismo do Estoril, Estoril, Portugal
³ Departamento de Biologia, Universidade de Évora, Évora, Portugal; E-mail: fcs@uevora.pt
⁴ Instituto de Investigação Cientifica Tropical, Lisboa, Portugal; E-mail: aalmeida@fmv.utl.pt (A.A.)
⁵ ITQB – Instituto de Tecnologia Química e Biológica, Oeiras, Portugal; E-mail: varela@itqb.unl.pt
⁶ Departamento de Química, Universidade de Évora, Évora, Portugal
⁷ Departamento de Zootecnia, Universidade de Évora, Évora, Portugal; ¥ E-mail: elsaba@uevora.pt
Abstract: Sheep, cow and goat, which are domestic ruminants of great economic interest in the Mediterranean region, although sharing the same pasture areas, ingest different levels of tannins. This suggests an ability to detect and adapt ingestion according to animal physiological limits of tolerance for these compounds. This review will detail the effects of dietary tannins on feeding behavior, and the role of the oral cavity in this process, with focus on these three domestic ruminant species. The role of salivary protein profile in tannin perception in the mouth, and as a defense mechanism, will be discussed.