2013 Annual Report
1a.Objectives (from AD-416):
1. Develop plant cell wall polysaccharide-based bioplastic composites with tailor-designed thermal, mechanical and biological properties for active packaging, construction and automotive materials.
2. Convert plant cell wall polysaccharides into biomedical materials for tissue regeneration, cosmetic personal care products, carriers of bioactive substances for the colon-specific delivery and to produce synbiotics (probiotic + prebiotic).
2a. Develop regeneration medicine and drug delivery biomedical products
2b. Develop skin-care biomedical products
3. Develop plant cell wall oligosaccharide-based prebiotics from agricultural processing residues rich in pectins and hemicelluloses and test the hypothesis that prebiotics can selectively promote the growth of gut bacteria associated with lean tissue growth to potentially control obesity.
3a. Conduct in vivo analysis of candidate prebiotics
3b. Discover new pectic and hemicellulosic prebiotics
3c. Determine if prebiotics can alter the colonic microflora to
potentially control obesity
4. Screen plant cell wall oligosaccharides for biological activity (anti-adhesion of pathogenic bacteria, immunomodulation, induction of apoptosis).
1b.Approach (from AD-416):
A multidisciplinary biorefinery approach will be used to develop health-related and biobased co-products from plant cell wall polysaccharides in fruit and vegetable processing residues. Plant cell wall polysaccharides will be converted into biomedical materials for human tissue regeneration, cosmetic personal care products, carriers of bioactive substances for colon-specific delivery and to produce synbiotics, in which probiotic bacteria are encapsulated in a prebiotic. Plant cell wall oligosaccharide-based prebiotics will be isolated from agricultural processing residues rich in pectins and hemicelluloses. The hypothesis that prebiotics can selectively promote the growth of gut bacteria associated with lean tissue growth to potentially control obesity will be tested. Plant cell wall oligosaccharides will also be screened for biological activity such as preventing the adhesion of pathogenic bacteria to intestinal epithelial cells, immunomodulation, and induction of cancer cell apoptosis. Bioplastic composites will be designed with bacteriocins for control of food-borne pathogens with active packaging. Weight-bearing, light weight bioplastic composites will also be produced with construction and consumer product applications in mind.
Research on the synthesis and characterization of bioplastics from agricultural byproducts continued. The technology developed for fabrication of bioplastics from sugar beet pulp and polylactic acid has been applied for compounding bioplastics from Ecoflex and banana peel. Research on the synthesis and characterization of active packaging materials continued. Bioplastics in combination with natural antibiotics, such as allyl isothiocyanate, thymol, or Nisaplin®, provide a new type of active packaging materials (APM) that have demonstrated excellent biological activity in suppressing the growth of Salmonella and Listeria. A new member of APM that released chlorine dioxide in response to environmental changes is under investigation. The preparation of devices from pectin and other food grade polysaccharides for colonic drug delivery continued. A series of in vitro experiments were designed and conducted to provide information to optimize the in vivo examination of rats that had demonstrated the capability of pectin-derived drug carriers to deliver protein-drugs or live bacteria to the colon. Furthermore, a human clinical trial of pectin derived controlled release particles for the therapy of colon inflammation is in progress. The preparation of 3-D porous devices from mixtures of pectin and hyaluronate has been completed and tested in rats for the effect on wound healing.
Research on novel plant cell wall oligosaccharides as potential bioactive functional food/feed ingredients continued. Hosted a post-doc from the Technical University of Denmark who characterized an arabinose-rich pectic oligosaccharide fraction from sugar beet produced by a major agri-business company in Finland. A swine feeding trial (64 piglets) was conducted at the ARS lab in Ames, IA using this sugar beet arabinose-rich pectic oligosaccharide diet for 21 days. Feces were collected at three times and qPCR analysis of microbial changes was conducted. Citrus fiber that consisted of mostly insoluble dietary fiber was rich in pectin and had in vitro prebiotic activity. Collaborated with a CRADA partner to scale-up production of modified citrus pectin with immunomodulation and potential anti-cancer activity. Conducted a series of bench-scale tests to optimize conditions for enzymatic depolymerization of commercial citrus pectin at the 2 kg level and then up to 50 kg scale in the ERRC Pilot Plant with the assistance of CRADA partner scientists. This was the first production of modified citrus pectin by this company in the U.S. and will help them find a domestic manufacturing partner.
Cranberry sugars to control urinary tract infections. Urinary tract infections cause millions of doctor visits annually by women, who suffer from this recurrent bacterial infection starting in their early twenties and lasting their entire life. Previously, the cranberry juice compounds proanthocyanidins associated with its red color were thought to be solely responsible for preventing Escherichia coli, a bacterium that causes the infection, from attaching to the urinary tract cells (epithelium). ARS researchers at Wyndmoor, Pennsylvania described the composition of sugar chains derived from and unique to cranberry pulp that prevented the adherence of E. coli to urinary tract cells, and a joint patent application was filed under a collaborative research and development agreement with a major cranberry product producer. These new cranberry sugars have potential to provide the consumer with another bioactive food ingredient to control urinary tract infections.
Low cost bioplastics from agricultural byproducts. Ecoflex (EF), which is a petrochemical-based, biodegradable material, and polylactic acid (PLA), which is derived from corn starch, are in demand by manufacturers to replace packaging materials which are not biodegradable or sustainable. We have shown that these materials when compounded with agricultural byproducts (AB), such as sugar beet pulp, make lower cost bioplastics that retain much of the properties of the petrochemical-derived plastics. However, many AB were incompatible with EF or PLA. Therefore, various AB were screened by ARS researchers at Wyndmoor, Pennsylvania and those found to be compatible with EF and PLA were water soluble and had a high length/diameter ratio. Banana peels (BP) were compounded with EF to form bioplastics, even at 70 % BP. This research demonstrates the potential for low cost commercial bioplastics derived from a steady supply of AB.
Yoo, H., Lee, B., Lee, H., Lee, S., Bae, I., Lee, H., Fishman, M., Chau, H.K., Savary, B.J., Hotchkiss, A.T. 2012. Structural characteristics of pumpkin pectin extracted by microwave heating. Journal of Food Science. 77:C1169-C1173.
Fishman, M., Chau, H.K., Qi, P.X., Hotchkiss, A.T., Yadav, M.P. 2013. Physico-chemical characterization of protein associated polysaccharides extracted from sugar beet pulp. Carbohydrate Polymers. 92:2257-2266.
Pang, Y., Sheen, S., Zhou, S., Liu, L.S., Yam, K. 2013. Antimicrobial effect of allyl isothiocyanate and modified atmosphere on Pseudomonas aeruginosa in fresh catfish fillet under abuse temperatures. Journal of Food Science. Volume 78(4)M555-M559.
Zhou, S., Sheen, S., Liu, L.S., Pang, Y., Yam, K.L. 2013. Antimicrobial effects of vapor phase thymol, modified atmosphere and their combination against Salmonella spp. on raw shrimp. Journal of Food Science. Volume 78(5):M725-M730.
Liu, B., Guevara, G.Z., Zhang, J., Liu, L.S. 2013. Performance enhancement of poly(lactic acid)/soy protein concentrate blends by promoting formation of network structure. Green Materials. 1(3):176-185.
Ray, S., Jin, Z.T., Fan, X., Liu, L.S., Yam, K. 2013. Development of chlorine dioxide releasing film and its application in decontaminating fresh produce. Journal of Food Science. 78(2):M276-M284.
Li, W., Jin, Z.T., Liu, L.S. 2012. Antimicrobial activity of allyl isothiocyanate used to coat biodegradable composite films as affected by storage and handling conditions. Journal of Food Protection. 75(12):2234-2237.