Non Technical Summary
This project supports the mission of the Agricultural Experiment Station by addressing the Hatch Act areas(s) of processing, distribution, safety, marketing, and utilization of food and agricultural products. Specifically, this project will focus on the pressing issue that healthy, fermented fruits and vegetables are difficult to make at industrial scales and are frequently subject to quality defects and inconsistent products with variable sensory profiles. Specifically, the project will assess the use of electrochemically driven methods and selected safe microorganisms to improve the control over fruit and vegetable fermentations. We expect that the results from this project will eventually lead to an expansion in low-cost, commercially-produced fermented fruit and vegetable foods with optimized sensory and nutritional characteristics. Increased availability of these foods will improve consumer access to fruits and vegetables, thereby lead to increasing daily intakes across the US population. The project specifically addresses the need for US manufacturing technologies to ensure a more sustainable, resilient, and healthy food supply. Broadly, we aim to develop innovative manufacturing technologies that increase improve food quality and nutritional value and that advance sciences and technologies to yield improved shelf life while minimizing food waste and loss throughout the food supply chain. The project also contributes to on-going efforts to provide all Americans with safe, nutritious food.

Classification

Knowledge Area (KA)	Subject of Investigation (SOI)	Field of Science (FOS)	Percent
501	5310	2020	50%
501	5310	1100	50%

Knowledge Area
501 - New and Improved Food Processing Technologies;

Subject Of Investigation
5310 - Machinery and equipment;

Field Of Science
2020 - Engineering; 1100 - Bacteriology;

Goals / Objectives
The over-arching goal of this project is to develop a novel, controllable, fermentation technology, termed Electro-Fermentation (EF) for precision production of fermented fruit and vegetables. EF is defined as electrochemically controlling microbial fermentation metabolism with polarizable electrodes. This technology takes advantage of our discovery that lactic acid bacteria (LAB), microorganisms essential for many food fermentations, possess a metabolism amenable to manipulation by EF. Our interdisciplinary team will use EF and LAB to modify fruit and vegetable fermentations with the following three objectives: (1) develop a closed-loop EF system for LAB fermentations controlled with a polarized anode that is monitored using real-time, oxidation reduction potential, pH, temperature, and electrochemical current read-outs; (2) apply EF and LAB starter cultures to modify juice and sauerkraut fermentations; (3) modulate EF using EF-guided starter culture selection.

Project Methods
In order to reach our goal of developing a closed-loop electro-fermentation (EF) system for the manufacture of fermented fruits and vegetables, we will test the overarching hypothesis that by modulating anode polarization based on real-time redox and pH measurements in a closed-loop configuration, it will be possible to control and improve fermentation outputs. To investigate this hypothesis, we will first build electrochemical cells and measure and modulate conditions to understand the range of anodic EF with a strain of Lactiplantibacillus plantarum, a species that is required for many fruit and vegetable fermentations. The studies will result in increasing the fermentation complexity in open and then subsequently closed-loop settings, with the latter defined by automatically varying the applied potential to track optimal redox, pH, current readings (Objective 1). Next, we will apply EF to modify juice and sauerkraut L. plantarum fermentations, with the goal of demonstrating the range of EF in simple and increasingly complex nutritive and microbial conditions (Objective 2). Lastly, we will aim to improve EF outputs by isolating and identifying EF-optimized L. plantarum and other bacteria from fruit and vegetable fermentations for use as starter cultures (Objective 3). Data collected from the three objectives will be analyzed with the appropriate controls and statistical tests. The results will be evaluated and interpreted in manuscripts and student theses. Efforts will be taken to share the results and interpretations with stakeholders at scientific conferences, at industry-directed meetings and events, and with the public via websites and national speaking opportunities. Evaluation of the outputs will encompass the timely publication of the experimental findings in high-tier microbiology and engineering journals and by documented industrial interest in adoption of the EF fermentation technology.