Source: UNIV OF IDAHO submitted to
Sponsoring Institution
National Institute of Food and Agriculture
Project Status
Funding Source
Reporting Frequency
Accession No.
Grant No.
Project No.
Proposal No.
Multistate No.
Program Code
Project Start Date
Sep 1, 2007
Project End Date
Jun 30, 2012
Grant Year
Project Director
Min, S.
Recipient Organization
MOSCOW,ID 83844-9803
Performing Department
School of Food Science
Non Technical Summary
Antimicrobial/antioxidant biopolymer edible films and coatings have recently been in the spotlight of food science for microbial safety. However, their commercial application in food industry has not been populated due to (i) high cost of pure biopolymer materials to purchase for commercial production; (ii) insufficient mechanical (tensile), barrier, and color properties of the film-coatings to be practically used; and (iii) lack of kinetic studies supporting the advantages of antimicrobial/antioxidant edible films and coatings against direct applications of antimicrobial/antioxidant substances. The purpose of this project is to develop biopolymer edible film-coatings that are practically applicable to commercial production of food products with their reduced material costs and improved mechanical, barrier, and color properties as well as antimicrobial/antioxidant properties.
Animal Health Component
Research Effort Categories

Knowledge Area (KA)Subject of Investigation (SOI)Field of Science (FOS)Percent
Goals / Objectives
(1) To develop edible biopolymer film-coatings using food industry wastes of potato peels, trout skins, and whey. (2) To improve mechanical (tensile), barrier, and color properties of the film-coatings to satisfy requirements for commercial application by optimizing film-forming variables and using a nano-emulsion technology. (3) To develop antimicrobial/antioxidant edible film-coatings by incorporating the bioactive compounds of nisin, plant essential oils, alpha-tocopherol, and quercetin into the film-coating matrices containing nano-emulsions. (4) To evaluate the effects of the antimicrobial edible film-coatings on model food systems of Hispanic cheese and salmon products contaminated with foodborne pathogens. (5) To evaluate the effects of the antioxidant edible film-coatings on the lipid oxidation of model food systems of peanuts and salmon products. (6) To test mathematical models for predicting the effectiveness of the films-coatings on the microbial inhibition in the food systems. The mathematical model will be used to predict the time during which the antimicrobials remain above the critical inhibiting concentration as well as the optimum film-coating thickness and initial concentrations of the antimicrobials for the safety for a given period of time. (7) To develop an edible film-controlled-released-packaging (EFCRP) using obtained diffusion parameters. (8) To evaluate potential to produce the films in an industrial scale using a co-rotating twin screw extruder.
Project Methods
Biopolymer edible film-coatings will be produced from the waste streams of potato peels, fish (trout) skin, and whey. Mechanical (tensile), barrier, and color properties of the biopolymer edible film-coatings will be enhanced to satisfy requirements for commercial application by optimizing film-forming variables and using a nano-emulsion technology. We are going to incorporate natural antimicrobials/antioxidants into the matrix of biopolymer-based-nano-emulsion films to develope antimicrobial/antioxidant-active packages (edible film-coatings). The antimicrobial film-coating is expected to show potential for inhibiting foodborne pathogens already present on food products, as well as for inhibiting their growth from contamination of film-wrapped or coated food products. Using mathematical models, we would be able to develop a method to predict requirements of antimicrobial/antioxidant edible film-coating for obtaining microbial safety or controlling lipid oxidation . For example, we would predict the time during which an antimicrobial remains above a minimum inhibitory concentration (MIC) on the film, as well as the necessary values for initial concentration of the antimicrobial and film-coating thickness for the inhibition for a selected period of time, using a MIC and previously-developed mathematical models. We also expect to identify factors most critical for controlling the release of active compounds and to elucidate relationships between compound migration and composition, processing, structure, and properties. This will greatly facilitate the development of both research and industrial-scale edible film technologies for food applications. The potential to produce the films in an industrial scale using a co-rotating twin screw extruder will be also evaluated in this research. Research collaborations will be made between the two campuses of University of Idaho and Washington State University.

Progress 09/01/07 to 06/30/12

OUTPUTS: No outputs. This person no longer works at the University of Idaho. PARTICIPANTS: Nothing significant to report during this reporting period. TARGET AUDIENCES: Nothing significant to report during this reporting period. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.

No Outomces/Impacts. This person no longer works at teh University of Idaho.


  • No publications reported this period

Progress 01/01/08 to 12/31/08

OUTPUTS: Two graduate (M.S.) students, a postdoc researcher, and a lab manager were involved in this project utilizing facilities in the School of Food Science in Univ. of Idaho. Research topics for the students' degree were derived from this project. Results from the research have been presented in a food science international conference (Institute of Food Technologists (IFT)) and prepared for publication in peer-reviewed scientific journals. Provisional patent applications have been made using data from this project. PARTICIPANTS: (1) Murali Krishna, Graduate (M.S.) student, School of Food Science (SFS), Univ. of Idaho (UI) (2) Nageshwar Tammineni, Graduate (M.S.) student, SFS, UI (3) Ho Jin Kang, Post-doc researcher, SFS, UI (4) Kathy Hendrix, Lab technician, SFS, UI (5) Caleb I. Nindo, Assistant Professor, SFS, UI (6) Shyam S. Sablani, Assistant Professor, Biological Systems Engineering (BSE), Washington State Univ. (WSU) (7) Florian Dasse, Grad student, ENSAR, Rennes, France (8) Luis Bastarrachea, Grad student, BSE, WSU (9) Sumeet Dhawan, Grad student, BSE, WSU TARGET AUDIENCES: Not relevant to this project. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.

A. Development of biopolymer films from potato peels, trout skin gelatin, and apple peels (1) Potato peel-based films: As processing pressure increased, the G' and the viscosity (at 90 C at 30 min) of the solution prepared with 10 passes increased. Those values of the solution prepared at 207 MPa increased as the number of passes increased. Water diffusivity and WVP decreased with low levels of glycerol. The water vapor permeability (WVP) increased as the glycerol content increased irrespective of the pressure and the number of pass. (2) Trout skin gelatin-based films: The G' values did not change dramatically (0.1-1.2 Pa), while the viscosity values increased steadily with time from 12 to 24198 Pa-s at 90 C. Tensile strength, % elongation at break, elastic modulus, water vapor permeability, % solubility, and CIELAB coordinate L*, a*, and b* values were 25.9 MPa, 17.3 %, 790.5 MPa, 2.7 g-mm/kPa-h-m2, 86.1 %, 88.5, -1.0, 2.6, respectively. (3) Apple peel-based films: The G' and viscosity decreased significantly with increasing processing pressure. The viscosity decreased from 644 to 468 kPa-s as the pressure increased from 138 to 207 MPa at 90 C. The monolayer water content decreased with increasing content of glycerol from 23 to 33%. Further increase in glycerol content did not change the monolayer water content. The water diffusion coefficient was highest at the intermediate level of glycerol content. WVP and oxygen permeability increased with increasing level of glycerol, while processing pressure did not influence the gas barrier properties of the films. The film prepared at 207 MPa was less stiff and strong, but more stretchable than those prepared at 138 and 172 MPa. B. Inhibition of Listeria monocytogenes by potato peel-based films with oregano essential oil An oil concentration of 30 µL/mL produced clear zones of inhibition. When the oil was incorporated into the PP film matrix, it continued to be active against Listeria monocytogenes at 10^4-10^6 CFU/plate. Films with 2% and 4% oil concentration produced clear zones of inhibition. The WVP values decreased significantly from 3.5 to 2.7 g-mm/kPa-h-m^2 as the concentration of oil increased from 0 to 2% in the film. As the concentration of oil in the film increased from 0 to 2%, TS and EM values decreased significantly from 6.3 to 2.9 MPa and 257.0 to 107.0 MPa, respectively. C. Physical and moisture barrier properties of fish gelatin films from extrusion Edible films with 1:0.2 and 1:0.25 ratios were successfully extruded with the temperatures of 110 and 120 C, a screw speed of 250 rpm, a liquid feed rate of 11 g/min, and a solid feed rate of 9 g/min. The 1:0.25 ratio extruded films had the highest % elongation (158.4%), while 1:0.2 ratio casted films had the highest tensile strength (26.4MPa). The WVP was higher for extruded films than casted films at the same gelatin-glycerol ratio, with WVP of 5.61 g-mm/(kPa-h-m2) being the lowest among the extruded films. The Tg of extruded films increased as temperature of the extrusion increased. The 1:0.2 films extruded at 110 C had the lowest Tg of 12.4 C.


  • ABSTRACTS: 1. Hendrix, K.M., Jin, T., and Min, S. 2008. Development of mustard meal co-product-used biopolymer edible films for food packaging. Institute of Food Technologists Annual Meeting. 053-14. June 30, 2008, New Orleans, LA.
  • 2. Hendrix, K.M. and Min, S. 2008. Biopolymer films from trout skin gelatin and commercial deep sea fish gelatin compared to whey protein films. 053-11. June 30, 2008, New Orleans, LA.
  • 3. Kang, H.J., Jin, T., and Min, S. 2008. Development of a potato peel-based edible film using high-pressure homogenization, ultrasound treatments and irradiation. Institute of Food Technologists Annual Meeting. 053-02. June 30, 2008, New Orleans, LA.
  • 4. Kang, H.J. and Min, S. 2008. Antioxidant activity of a potato peel extract as a natural antioxidant. Institute of Food Technologists Annual Meeting. 096-47. June 30, 2008, New Orleans, LA.
  • PAPER & PAPER IN PROCEEDINGS: 1. Min, S. and Choi, Y. J. 2009. Microbial Modeling in Quantitative Risk Assessment for the Hazard Analysis and Critical Control Point (HACCP) System: A Review. Food Sci Biotechnol.
  • 2. Min, S.C., Kim, Y.T., and Han, J.H. 2009. Packaging and the Shelf Life of Cereals and Snack Foods. In: Robertson, Gordon L., editor. Food Packaging and Shelf Life: A Practical Guide. Oxford, UK: CRC Press, Taylor & Francis Group.

Progress 01/01/07 to 12/31/07

OUTPUTS: 1. Antioxidant activity of potato peels was determined as a background study for developing edible biopolymer edible films from potato peels. 2. Biopolymer films were developed from potato peels and fish skin gelatin. 3. Extrusion conditions were determined for producing whey protein films. PARTICIPANTS: Kathy Hendrix, Department of Food Science and Toxicology, University of Idaho, Moscow, ID. Ho Jin Kang, Department of Food Science and Toxicology, University of Idaho, Moscow, ID. Armando McDonald, Department of Wood Chemistry & Wood Composites, University of Idaho, Moscow, ID. Tony Jin, Food Safety Intervention Technologies Research, United States Department of Agriculture, Wyndmoor, PA. TARGET AUDIENCES: Potato and trout process industries.

1. Antioxidant activity of a potato peel extract as a natural antioxidant: The 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging assay and the 2- thiobarbituric acid reactive substances (TBARS) value test were conducted to determine antioxidant activity of potato peels. The results from the TBARS test indicated that a potato peel extract is a potential material to be used as a natural food antioxidant. 2. Development of edible biopolymer edible films: A potato peel solution was treated by homogenization at high-pressure (22,000 psi, 25-50 C), ultrasound (400 W, 24 kHz, 120 micrometer, 30-60 C, 30 min), or gamma-irradiation (10-20 kGy) to obtain small biopolymer particles in the solution. A fish skin gelatin solution was prepared with tout skin-extracted gelatin and commercial fish gelatin (6.8% (w/w)). The solutions were heated to 90 C for 30-60 min. After cooling, 10-100% (w/w) glycerol of potato peel was added to form a film-forming solution. Films were formed by casting degassed film-forming solutions and their film properties of tensile properties, water vapor permeability, water solubility, and color (lightness) were measured. The film properties of the potato peel-based film produced from the homogenized (22,000 psi) film-forming solution were better than those of the films from the solutions treated by ultrasound or irradiation. The tensile strength, % elongation at break, and elastic modulus, water vapor permeability, and solubility of the film were 4.9 MPa, 14.4%, 101.7 MPa, and 27.4%, respectively. The fish gelatin films exhibited better film properties compared to the WPI films, with the exception of solubility. The tensile strength, % elongation at break, elastic modulus, and water vapor permeability of the films were 10.6 MPa, 6.2 %, 313.7 MPa, and 3.5 g-mm/kPa-h-m2, respectively, for trout skin films, 23.0 MPa, 37.3 %, 600.5 MPa, and 2.3 g-mm/kPa-h-m2, respectively, for commercial fish gelatin films. Trout gelatin films and commercial fish gelatin films had 76.4 and 100% (w/w) soluble matters, respectively, as compared to WPI at 19% soluble matter. Fish gelatin films have slightly better clarity than WPI films. Potato peels and fish (trout) skin waste have potential value as protein and natural product sources that can be utilized to form biopolymer films for practical applications in the food industry. 3. Production of whey protein edible films by extrusion: Extrusion was investigated for producing whey protein films in a large scale. A co-rotating twin screw extruder (Haake-Leistritz Micro-18, Sommerville, NJ) was used to produce the films. The screw speed and the production temperature were controlled at 200-300 rpm and 120-150 C, respectively. We identified temperature profiles in barrel, screw type, screw speed, production rate (wet feed and dry feed), water content, and plasticizer (glycerol) content as major variables in producing whey protein films by extrusion. Whey protein-based sheets containing 48.8% glycerol (dry basis) were obtained at screw speeds of 200, 225, 275, and 300 rpm. Feed rates were proportionally decreased or increased depending on the screw speed.


  • No publications reported this period