Chitosan as a Functional Food

1. Chitosan as a Functional Food Creative Commons Sabrina Hannah PhD Candidate Food Science and Technology

2. What is Chitosan? • Polysaccharide - copolymer of: • glucosamine • N-acetyl glucosamine • Chitosan oligosaccharides also important • Derived from chitin • 2nd most abundant naturally occuring polysaccharide • Anthropod shells, fungi, brown algae Creative Commons

3. Chitin Chitosan

4. Potential Health Effects

5. Chitosan and Dietary Fats • Fats Bound Include: • Fatty Acids • Bile acids • Triglycerides • Cholesterol • Other sterols Shahidi, et al, 2004 Hennen, 1996

6. Weight Loss & Cholesterol Lowering Effects • Demonstrated effective in animal and human trials • Most effective in combination with diet adjustment • Effectiveness is enhanced by ascorbic acid • Properties and means of administration are important

7. Fat Digestion in Rats fed Chitosan Fig. 2. Apparent digestibility of fats and proteins by rats fed with cellulose or chitosan. The apparent fat digestibility was calculated as 100 [(ingested lipids - fecal lipids) / ingested lipids]. Abbreviations: CE,cellulose; CEA, cellulose with ascorbic acid; CEN, cellulose with sodium ascorbate; CH, chitosan; CHA, chitosan with ascorbic acid; CHN, chitosan with sodium ascorbate. chitosan + sodium ascorbate chitosan chitosan + ascorbic acid Deuchi et al, 1994

8. Cholesterol Lowering in Obese Adult Humans modified from Veneroni et al, 1996

9. Is it really effective? • Recent review by Ni Mhurchu et al (2005) • Randomized controlled studies involving at least 4 week supplementation • 14 studies, 1071 participants • Dose varied from 1 g/day to 15 g/day • Found weighted mean difference in weight of -1.7 kg and cholesterol of -0.2mmol/L • Statistically significant differences, but perhaps not clinically significant

10. Chitosan oligosaccharides improved growth and growth rate of many Lactobacillus sp. and B. Bifidum sp. Chitosan as a Prebiotic Lee et al, 2002

11. Antitumor Properties: Chitosan Oligosaccharides • Suzuki et al, 1996, 1992, 1986, 1985 • Immuno-enhancing effect observed in mouse model • Tokoro et al, 1988 • growth-inhibitory effects observed in a mouse model • Tsukada et al, 1990 • antimetastic effects in mice with lung cancer • Kim and Kim, 2006 • Inhibits activation and expression of MMP-2 in human dermal fibroblasts

12. Calcium Adsorption: Helps or Hurts? • Jeon and Kim, 1997 • Decreased fecal calcium excretion with intake of chitosan oligosaccharides • Breaking force of rat femurs enhanced by chitosan consumption • Wada et al, 1997 • Chitosan accelerated urinary excretion of radiolabeled calcium • Rats fed chitosan exhibited higher retention then rats fed cellulose • Deuichi et al (1995) • Mineral adsorption and bone mineral content decreased by consumption of chitosan in rats

13. Safety and Health Concerns • LD50 in mice found to be 16 g/day/kg (Kinumaki, 1968) • Gastric dehydration and impaction • Equates to >90 g/day in humans (Hennon, 1996) • Potential Negative Health Effects: • Growth retardation • Reduced absorption of fat soluble vitamins and nutrients • Metabolism of beneficial fats prevented • Alteration of gut microflora • Potential allergy issues

14. Regulatory Issues • United States • 1983: approved by USDA as a feed additive • 2001: GRAS status request filed but recalled • Primex (http://www.primex.is/) • Widely avaliable as a supplement • Japan, Europe, England, Italy: • Used as a food preservative • Used as a food additive • Used as a diet aid • Chitosan containing products including dietary cookies, potato chips, & noodles are widely available

15. Other Applications

16. As an Antimicrobial • Demonstrated effective against: Candida, E. Coli, and Staph. Aureus, Bacillus cereus, Proteus vulgaris • Evaluated for foods including: fruit juices, emulsified sauces, meat, mayo, tofu, hummus, salads, shrimp • Demonstrated effective against fungal diseases on strawberries, kumquats, apples, carrots, pea pods, pizza and meats • Effective against fungal pathogens Shahidi, et al, 2004 Jeon et al, 2000

17. As an Edible Film • Preservative film for fruits and vegetables • Antimicrobial and Antifungal • Ripening delay • Slow respiration rate • Evaluated on: peaches, pears, kiwifruit, cucumbers, bell peppers, strawberries, tomatoes • Browning prevention • Demonstrated on Lichi (Zhange and Quantick) • Anthocyanins, flavonoids, and phenolics were effected • Potential to replace collagen for meat casing applications Shahidi, et al, 2004 Jeon et al, 2000 Bough, 1977

18. As an Antioxidant • Darmadji and Izumimoto, 1994 • Decrease in beef TBA values with addition of chitosan • St. Angelo and Vercellotti, 1989 • Decrease in beef TBA values and hexanal levels • Control of “warmed-over flavor” with addition of N-carboxymethylchitosan • Li et al, 1996 • Oxidative rancidity of pork prevented by N-carboxymethylchitosan • Kamil et al, 2002 • Oxidation prevention in cooked herring observed through peroxide values, TBARS and volatile aldehydes

19. As an Additive or Processing Aid • Juice Clarification • Control of acidity in juices • Color adjustment/stabilization • Texture control • Thickener • Stabilizer • Gel former • Emulisifying agent Shahidi, et al, 2004 Jeon et al, 2000 Bough, 1977

20. Questions?