Research Project: Reducing Postharvest Loss and Improving Fresh Produce Marketability and Nutritive Values through Technological Innovations and Process Optimization

Location: Food Quality Laboratory

2024 Annual Report

Objectives
Objective 1. Enhance key organoleptic and nutritional qualities of major horticultural crops using emerging production and post-harvest handling practices. Sub-obj. 1A. Improve food quality and nutrition, and harvesting efficiency for vegetables grown via controlled environment agriculture (CEA). Sub-obj. 1B. Develop novel technologies to support NASA’s mission in growing microgreens in space. Objective 2. Reduce post-harvest loss and waste and enhance marketability of fresh produce. Sub-obj. 2A. Non-destructive monitoring of produce quality and maturity via a paper sensor. Sub-obj. 2B. Improve quality and shelf life of fresh produce through collaborative breeding and cultivar selection. Sub-obj. 2C: Predicting consumers’ preferences for fruits and vegetables through advanced analyses of digital imagery and emotions. Objective 3. Improve product quality and sustainability through novel fresh-cut processing technologies and process optimization. Sub-obj. 3A. Develop novel fresh-cut produce wash and disinfection technologies for comprehensive improvement in food quality and safety. Sub-obj. 3B. Determine chemical profile of fresh-cut produce wash water in support of cost-effective water treatment and reuse. Sub-obj. 3C. Assess the potential use of nanoparticle coatings on the contact surface of equipment to optimize fresh-cut processing.

Approach
This project takes an integrated and holistic approach to tackle major food security problems by supporting efficient growth and harvesting of nutrient-dense food products and reducing post-harvest food loss and waste. This project consists three objectives. In objective 1, we will investigate the effect of light wavelength, intensity, and photoperiod on the growth, sensorial quality, and phytonutrient content of specialty vegetables. We will develop mechanical devices to facilitate harvesting of microgreens while minimizing tissue damage. We will also develop and/or evaluate soil mixes and soil-less growth media for seed fixation in microgravity. In objective 2, our team of scientists will collaborate with ARS breeders to identify lettuce cultivars resistant to enzymatic browning and having improved post-harvest quality and shelf life. We will continue collaborating with our university partner (and co-inventor) to advance our patent-pending paper sensor array for nondestructive quality evaluation. In objective 3, we will work with our industry partners to further develop, optimize, and commercialize our patented produce washing and disinfection technology. We will develop and optimize a novel in-flight washing system to improve the food quality and safety of fresh-cut products. This will be a continuation and expansion of the patented in-flight washing technology developed under a previous project. We will also investigate the major chemical components of fresh-cut produce wash water and develop approaches to support safe and cost-effective water reuse. Specifically, we will identify major compounds present in produce; their release during cutting; their reactivity with free chlorine during different washing stages; how such reaction contributes to the loss of free chlorine in wash water, and to difficulties in maintaining adequate chlorine levels; the type and amount of harmful disinfectant byproducts thus produced during washing; and effective methods to remove or mitigate the chemical oxygen demand (COD) and chlorine demand (CLD) in wash water during fresh-cut processing.

Progress Report
Progress was made on all 3 Objectives and their Sub-objectives, all of which fall under NP306, Produce Quality and New Uses. Progress on this project centers on enhancing key organoleptic and nutritional qualities of major horticultural crops using innovative controlled environment agricultural production, novel post-harvest handling technologies, and process optimization, reducing post-harvest losses and enhancing the marketability of fresh produce. In support of Objective 1, we made major progress and technological breakthrough in several forefronts. First, we invented a novel 3D microgravity simulator featuring multiple stages and multispectral modulation capacity. This unique instrument allows simultaneous studies on the response of plant or microorganism samples to a diversity of precisely controlled light regimes. This patent-pending technology fills a critical void in space biology research instrument. Second, we have developed multiple forms of soilless growth substrates including hydrogels, aerogels, and ion foams from natural polymers (e.g., polysaccharides) and wood waste materials. The lightness, biodegradability, biocompatibility, strong water retention capacity, and desirable plant growth performance make those novel materials an attractive alternative to mineral-based and non-sustainable substrates such as Styrofoam, peat moss, and Rockwool. This technique has prompted an ongoing study on the high-throughput growth substrate screening empowered by robotic- and machine learning, which is being conducted in collaboration with the Autonomous Materials Discovery Lab at the University of Maryland. Third, we started new research on the light modulation of growth, sensory properties, and post-harvest attributes of basils in controlled environment agriculture operations. We found that basil plants grown under supplementary blue, far-red, and blue + far-red lights exhibited distinct canopy sizes, stem lengths, leaf thicknesses, and leaf colorations. Furthermore, light treatments altered the aroma of basil and improved post-harvest performance. Therefore, specific wavebands of light can be used to alter basil growth and create distinct aromatic profiles. In support of Objective 2, we continued to test a novel chromogenic sensor array developed by our collaborator for detecting plant pathogens affecting produce and floral plants in vivo, including Ralstonia and Pseudomonas. Although nine indicators responded to the VOCs within 24 hours in vitro, but needed to be modified for in vivo. These results will be used for the further development and optimization of the sensor array and shed light on the opportunities and challenges of this technique in fresh produce quality and plant pathogen monitoring. Further, in this objective we were able to conduct biometrics work that target behavior prior to choice-making of panelists to online images with different constructions. Results demonstrated patterns that can serve as basis for an eventual framework to help industry inform online consumers. Factors such location of labeling, familiarity of the shape of the fruit, homogeneity of the color, name of the variety alters the duration of attention in different points of interest of the virtual image. Moreover, an eye-tracking pilot study with fresh-cut lettuce revealed that online consumers focus on defective or browning areas when examining fresh vegetable before purchasing. Our initial results are promising to provide a list of recommendations for introducing produce in online settings. In support of Objective 3, we completed testing of the optimized inflight washer (IW) for product quality and shelf, water and sanitizer usage, and process efficiency. Our concept of pre-wash rinse to reduce organic matter has been adopted by the industries. We also completed systematic characterization of chlorine disinfection byproduct and off-gas in relation to fresh-cut wash and disinfection process. Thanks to our collaborators at Texas A&M University we were able to develop in-house nano particle coatings, which were tested on plastic (HDPE), wood and stainless-steel surfaces. Different particle sizing and hydrophobicity degrees were obtained with mixed results across different microorganisms tested. The results are being used to further adjust properties of coatings prior to assess performance in a washing/packaging system that we have already set up to obtained results in conditions similar to those in postharvest operations.

Accomplishments
1. Developed water-efficient, sustainable, and biodegradable growth substrates for fresh vegetables, on Earth and in space. Growth substrates play a pivotal role in plant establishment and development. Soilless growth substrates have attracted increasing interest against the backdrop of shrinking arable land and food safety concerns linked to open-field operations. Researchers in Beltsville, Maryland, developed a post-crosslinked biopolymer-based hydrogel, which can be easily transported and stored in dry state and then re-hydrated conveniently into a stable and highly porous substrate when needed. This technology has proven successful in mustard (Brassica juncea) microgreen cultivation under both standard growth conditions as well as simulated microgravity generated with a clinostat. The biodegradability, biocompatibility, lightness, and desirable plant growth performance make those novel materials an attractive alternative to mineral-based and non-sustainable substrates such as Styrofoam, peat moss, and rockwool. Accomplishment was featured in the USDA’s 100th Annual Agricultural Outlook Forum and at USDA’s 1st Agrifood Innovation Forum.

2. Comprehensive improvement in food quality and safety of leafy greens via multispectral modulation. LED growth lights are widely used in the production of leafy greens in the controlled environment agriculture (CEA). While the effects of light spectra and intensity on photosynthesis and crop yield have been extensively studied, little is known regarding their impacts on microbial growth, survival or die-off on leafy greens, and the consequence on food safety and quality. Pioneering research by the Researchers in Beltsville, Maryland, discovered and exploited the unique multifaceted impacts of blue light on microbial growth and survival, and the changes in surface property and metabolic profiles. Given that blue LEDs are broadly used in CEA production, our findings revealed an effective and cost-efficient approach to integrated improvement in food safety, quality, and shelf life during CEA operations.

3. Groundbreaking research revealing the potential to conserve half of peanut kernels used as seed for food. Sustainable production of nutrient-rich peanuts faces a unique challenge: seed has long been the largest cost factor in peanut production, accounting for over 20% of the total production cost. This is due to the large acreage used for peanut productions, but also due to the low germination and survival rate of the peanut kernels. Sought out by peanut industry stakeholders and other peanut experts, as well as an ARS administrator, Researchers in Beltsville, Maryland, conducted a groundbreaking study, using only half of the peanut kernel (one cotyledon containing the embryo) as the seed, with the other half used as food. The team investigated the effects of cutting and splitting peanuts on seed germination, plant growth, flower development, peanut pod formation, and production yield in potting soils and demonstrated, for the first time, the feasibility of growing peanut plants from partial peanut kernels without the costly tissue culture process. The team further identified opportunities to improve peanut kernel germination and plant growth via the use of ultrasound. This accomplishment could generate additional peanut food products without compromising seed supply. This technique will provide peanut farmers with an additional income stream and improve the food and nutrition security for the consumers.

4. A novel multi-stage, 3-dimensional microgravity simulator with multi-spectral modulation that filled a critical instrument void for space biology research. The world has entered a new era of space exploration. Advancement in space technology has become the new frontier in global competition. As we move closer to undertaking long-duration space exploration, a deep understanding of the effects of microgravity (during spaceflight) and reduced gravity (during life on the Moon and Mars) on humans, animals, and plants is critical. While space biology research often requires multiple platforms for the simultaneous evaluation of multiple treatments, replications, or sample compartmentation under identical microgravity and environmental conditions (temperature, humidity, atmospheric composition, etc.), the lack of technologies and devices to support these hinder the progress. In responding to this critical challenge, Researchers in Beltsville, Maryland, have designed and prototyped a novel 3D microgravity simulator with multiple platforms and multi-spectral modulation capabilities. This invention enables many space biology research studies to be conducted simultaneously with better precision and repeatability.

Review Publications
Boyd, A., Luo, Y., Lunney, J.K., Kustas, B., Fukagawa, N.K., Mattoo, A.K., Crow, W.T., Pachepsky, Y.A., Kim, M.S., Lillehoj, H.S., Van Tassell, C.P., Zhang, H.Q., Blomberg, L., Dubey, J.P. 2023. Cross-cutting concepts to transform agricultural research. Frontiers in Sustainable Food Systems. 7. Article e1242665. https://doi.org/10.3389/fsufs.2023.1242665.
Gu, G., Ding, Q., Redding, M., Yang, Y., O'Brien, R., Gu, T., Zhang, B., Zhou, B., Micallef, S.A., Luo, Y., Fonseca, J.M., Nou, X. 2024. Differential microbiota shift on whole romaine lettuce subjected to source or forward processing and on fresh-cut products during cold storage. International Journal of Food Microbiology. https://doi.org/10.1016/j.ijfoodmicro.2024.110665.
Peng, H., Luo, Y., Teng, Z., Zhou, B., Pearlstein, D.J., Wang, D., Turner, E.R., Nou, X., Wang, T.T., Tao, Y., Fonseca, J.M., Simko, I. 2024. Genome-wide association mapping reveals loci for enzymatic discoloration on cut lettuce. Postharvest Biology and Technology. 207. Article 112577. https://doi.org/10.1016/j.postharvbio.2023.112577.
Teng, Z., Luo, Y., Sun, J., Pearlstein, D.J., Oehler, M., Fitzwater, J.D., Zhou, B., Hussan, M.A., Chang, C.Y., Chen, P., Wang, Q., Fonseca, J.M. 2024. Effect of far-red light on biomass accumulation, plant morphology, and phytonutrient composition of ruby streaks mustard at microgreen, baby leaf, and flowering stages. Journal of Agricultural and Food Chemistry. 72(17):9587–9598. https://doi.org/10.1021/acs.jafc.3c06834.
Wu, Y., Pham, Q., Wang, Y., Huang, H., Jiang, C., Yu, L., Li, R.W., Wang, J., Luo, Y., Wang, T.T. 2023. Red cabbage microgreens modulation of gut microbiota is associated with attenuation of diet-induced obesity risk factors in a mouse model. Journal of Agricultural and Food Chemistry. https://doi.org/10.1039/d3fo01249b.
Wu, Y., Xin, M., Pham, Q., Gao, Y., Huang, H., Jiang, X., Li, R.W., Yu, L., Luo, Y., Wang, J., Wang, T.T. 2023. Gut microbiome changes elicited by dietary red cabbage is associated with attenuation of high fat diet-related risk factors in a rodent diet-induced obesity model. Foods. https://doi.org/10.20944/preprints202312.1628.v1.
Luciano-Rosario, D., Peng, H., Gaskins, V.L., Fonseca, J.M., Keller, N.P., Jurick II, W.M. 2023. Mining the penicillium expansum genome for virulence genes: A functional-based approach to discover novel loci mediating blue mold decay of apple fruit. The Journal of Fungi. 9(11). Article e1066. https://doi.org/10.3390/jof9111066.
Park, E., Luo, Y., Zhou, B., Fonseca, J.M., Stommel, J.R. 2024. Varied attributes of jalapeño pepper cultivars influence fresh-cut product quality. Journal of the American Society for Horticultural Science. 149(3):152-161. https://doi.org/10.21273/JASHS05346-23.
Bartholomew, H.P., Lichtner, F., Bradshaw, M., Gaskins, V.L., Fonseca, J.M., Bennett, J., Jurick II, W.M. 2022. Comparative Penicillium spp. transcriptomics: conserved pathways and processes revealed in ungerminated conidia and during postharvest apple fruit decay. Microorganisms. 10(12). Article e2414. https://doi.org/10.3390/microorganisms10122414.
Bartholomew, H.P., Luciano-Rosario, D., Bradshaw, M., Gaskins, V.L., Peng, H., Jurick II, W.M., Fonseca, J.M. 2023. Avirulent isolates of Penicillium chrysogenum to control blue mold of apple caused by P. expansum. Microorganisms. 11(11). Article e2792. https://doi.org/10.3390/microorganisms11112792.
Teplitski, M., Fonseca, J.M. 2024. Biotechnologies and bioinspired approaches for reducing loss and waste of foods of plant origin. Current Opinion in Biotechnology. 85. Article e103028. https://doi.org/10.1016/j.copbio.2023.103028.
Shrestha, S., Barvenik, K.J., Chen, T., Yang, H., Kesavan, M.M., Little, J.M., Teng, Z., Luo, Y., Tubaldi, E., Chen, P. 2024. Machine intelligence accelerated design of conductive MXene aerogels with programmable properties. Nature Communications. 15. Article e4685. https://doi.org/10.1038/s41467-024-49011-8.
Mao, Y., Ma, P., Li, T., Liu, S., Wang, X., Chen, G., Xie, H., Brozena, A.H., Zhou, B., Luo, Y., Cheng, H., Wang, Q., Briber, R.M., Hu, L. 2024. Flash heating process for efficient meat preservation. Nature Communications. 15. Article e3893. https://doi.org/10.1038/s41467-024-47967-1.
Wang, D., Luo, Y., Zhang, B., Xu, Y., Yu, H. 2023. SQ-Swin: Siamese Quadratic Swin transformer for lettuce browning prediction. IEEE Access. 11:128724-128735. https://doi.org/10.1109/ACCESS.2023.3332488.