Grantee Research Project Results
Final Report: Reduction of Water Consumption and Pollution in the Corn Masa Production Process
EPA Grant Number: SU834326Title: Reduction of Water Consumption and Pollution in the Corn Masa Production Process
Investigators: Okos, Martin R. , Najm, Majdi Abou , Piepenburg, Jayne , Probst, Kyle , Birt, Lindsey , Zawadsky-Weist, Maya
Institution: Purdue University
EPA Project Officer: Page, Angela
Phase: I
Project Period: August 15, 2009 through August 14, 2010
Project Amount: $9,112
RFA: P3 Awards: A National Student Design Competition for Sustainability Focusing on People, Prosperity and the Planet (2009) RFA Text | Recipients Lists
Research Category: Pollution Prevention/Sustainable Development , P3 Challenge Area - Chemical Safety , P3 Challenge Area - Safe and Sustainable Water Resources , P3 Awards , Sustainable and Healthy Communities
Objective:
Research was conducted based on the hypothesis that a reduced waste nixtamalization process can significantly reduce waste disposal and water usage without affecting quality of product. Due to minor set-backs in the original procedure, most of the research focus was on development of a reduced waste nixtamalization process with minor emphasis on the value added product removal.
Specific Research Objectives were to:
- Determine the chemical properties of nejayote wastewater from multiple masa manufacturing facilities from the United States and Mexico.
- Identify, explore (pilot test), and compare the impact of recycling the nejayote on the buildup and composition of value added components in the nejayote.
- Identify, explore (pilot test), and compare different methods of recovering a value added product from the nejayote.
- Evaluate the effectiveness of different quantities and qualities of value added products obtained using different proposed solutions and processes.
- Perform a matrix analysis to propose an optimum process to recover a value added product that will reduce overall pollution levels (the main objective of the study) taking into consideration the various costs, effectiveness of proposed method, quality of recovered product, and users’ acceptance constraints.
Summary/Accomplishments (Outputs/Outcomes):
Results from the Phase I project indicated that the laboratory-scale reduced waste nixtamalization process (RWNP) was successful by achieving the goal of reducing the waste by 10%. During the course of the experiments conducted from August 2009 to March 2010 at Purdue University, we tested and modified an RWNP two times by doing 18 total trials. The outcome resulted in the discovery of a feasible nixtamalization process that reduced energy by 70%, reduced water usage by 55%, and cut down waste disposal by 82%. The RWNP demonstrated that the reuse of cook/steep water in the original process is a viable option for a reduced-waste masa production scheme. The wastewater from the traditional nixtamalization process (TNP) and from the RWNP was comparable based on water quality, water amount, and dry matter content. The final product (masa) was evaluated based on masa pasting characteristics, nixtamal moisture content, and a tortilla sensory evaluation.
Moisture content of the nixtamal decreased slightly across the reuse trials from 55 to 48%, which is still within the desired moisture content range for tortillas of 50-48% (Serna- Saldivar, et al., 1993). Dry matter content of the cooking (reuse) water increased over the course of the reuse trials from 2 to 7%. Trends indicate that the moisture content values would level off to 46-48%, while the dry matter content would level off to 13%. Final product quality did not change as evaluated by the pasting characteristics and sensory test. More testing is necessary to determine the real level-off values for solids and moisture content. The results of the evaluation indicate that there is no significant change in the pasting viscosity of the masa from the TPN, where water is not reused, and the RWNP, with the reduced waste scheme.
Conclusions:
The results of our research have implications for economic prosperity, environmental sustainability, and the general society. The results show that an RWNP improved the sustainability of the masa production process by reducing energy, water usage, and waste disposal without significantly affecting the quality or quantity of masa produced.
The reuse of nixtamal in the masa production process is potentially feasible, and is an economically viable solution; masa producers save money on water and wastewater treatment. The reduced-waste procedure benefits society at large in that it not only saves money, but also conserves water. In times when water scarcity is an increasing threat globally, any means of conserving water can help make a difference in tomorrow's resources. The process not only conserves water, but reduces waste. The local environment benefits from the process, as environmental side effects of untreated waste disposal, such as increased algal growth and oxygen depletion in surface waters, are minimized. Locally improved water quality also provides a better habitat for aquatic life.
Future work should involve further laboratory studies to optimize the laboratory process by determining a more definitive level-off value for dry matter and moisture content, and proceed to scale up the procedure to make it more readily applicable for industry use.
Proposed Phase II Objectives and Strategies:
Based upon the results of the Phase I project, more work is needed to fully optimize and implement the sustainable RWNP design into the food manufacturing industry. The overall objective for Phase II of the project is broken down into two stages. The first stage is to develop and optimize a tortilla manufacturing process that reduces energy and water use, and the second stage is to reduce waste followed by scale-up and validation for industry incorporation.
The specific objectives of this project are to:
- Determine the effect of process water recycling on the quality of the finished product.
- Evaluate and develop a modified RWNP that resolves the setbacks associated with the original RWNP procedure.
- Perform additional reuse trials using the modified RWNP and determine the physical and chemical properties of corn masa.
- Use laboratory data to develop empirical models to optimize modified RWNP.
- Use a model for pilot scale up to produce tortillas using the modified RWNP.
- Perform sensory analysis on tortillas to determine consumer acceptability.
- Based on results from sensory analysis, provide recommendations to implement the modified RWNP as a new product line in the food production industry.
The hypothesis for Phase II is that an optimized cost-effective, zero-discharge masa manufacturing process that simultaneously minimizes energy and water use can be developed and demonstrated. Laboratory experiments will be conducted to determine important process parameters and their affect on the physical and chemical characteristics of final product quality. Data from the experiments will be used to develop empirical models used for scale up and design of a pilot scale production line. This production line will produce a new type of whole grain tortilla that is different from the traditional one in that the tortillas will be produced from a zero-waste process. Consumer acceptability will be assessed by a sensory evaluation panel. Further work will include setting up teaching workshops through the Food Processing Environmental Assistance Center (FPEAC) at Purdue University to enhance sustainable development within the food industry around the world.
We propose that our design can be implemented in the food manufacturing industry. The goal will be to create a new processing line rather than change existing infrastructure because food manufacturers are reluctant to change. Rather, we plan to use the sustainable process as a marketing tool to enhance customer demand. Advertising a new, whole food product that is manufactured using a low-energy, low-cost, low-pollution process would be attractive in the eyes of the consumer. By setting up teaching workshops using the pilot- scale process as a demonstration, this idea can be effectively infiltrated into not only masa production facilities in Mexico but food manufacturers throughout the global food industry.
Journal Articles:
No journal articles submitted with this report: View all 1 publications for this projectSupplemental Keywords:
recovery and reuse of materials through system design, sustainable urban planning, environmentally benign endpoints, resource recovery,sustainability, process sustainability, cultural sustainability, green manufacturing,Relevant Websites:
The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Conclusions drawn by the principal investigators have not been reviewed by the Agency.