Location: Healthy Processed Foods Research
2019 Annual Report
Objectives
The goal of this research is to continue the investigation, development and commercialization of several new infrared (IR) and ultraviolet (UV) based processing technologies including infrared drying, dry blanching, sequential infrared (IR) dry-blanching/dehydration and hot air-drying (SIRDBHAD), and
combined IR and UV disinfection, and IR dry-peeling of specialty crops. Further goals of this research are to use new process technologies including microwave, solar thermal, vacuum forming, casting, extrusion, pasteurization, and homogenization, alone or in combination, to add value to specialty crops. Specific objectives are listed below:
Objective 1: Enable new, efficient and sustainable commercial infrared and ultraviolet based methods for processing specialty crops to improve food quality, value and safety.
Sub-objective 1.1 Investigate and commercially demonstrate an energy efficient drying technology for producing high quality nuts.
Sub-objective 1.2 Investigate, demonstrate, and commercialize a novel IR technology for producing healthy crispy snacks.
Sub-objective 1.3 Develop IR heating and ultraviolet (UV) technology for improved drying efficiency and safety of nuts.
Sub-objective 1.4 Develop sustainable IR peeling technologies for fruits and vegetables.
Objective 2: Enable economical, input-efficient and sustainable commercial microwave and solar thermal methods for processing specialty crops while improving product quality and value.
Sub-objective 2.1. Develop microwave systems for drying and extracting high-value compounds from specialty crops and their co-products.
Sub-objective 2.2 Develop a medium-scale solar thermal cabinet dryer with the capability to operate 24 hours a day during specialty crop harvest periods.
Sub-objective 2.3 Develop solar thermal alternatives for heat-intensive specialty crop processing unit operations beyond cabinet drying.
Objective 3: Enable novel, value-added commercial forming, casting and extrusion methods for processing fruits, vegetables and legumes with improved food safety and nutrition.
Sub-objective 3.1 Develop vacuum forming technologies that can be implemented to increase utilization and consumption of specialty crops and their co-products in a variety of nutritious and value-added forms.
Sub-objective 3.2 Apply the tools of nanoscience to the casting of edible films to improve safety, extend shelf-life and improve quality.
Sub-objective 3.3 Develop healthy and sensory enhanced, ready-to-eat extruded healthy foods from legumes, specialty crops, cereals, fruits and vegetables and their fractions.
Objective 4: Enable new, commercial methods of pasteurizing legumes and specialty crop-based beverages and yogurts, for improved flavor, bioactives and shelf life.
Approach
The research and development of new processing technologies can add value to
specialty crops through the development of new foods containing up to 100%
specialty crop based ingredients with enhanced healthfulness, convenience, and overall consumer appeal. Increased consumption of nutritious fruit, vegetable, nut, and legume based foods will improve the American diet and reduce the prevalence of obesity in our nation. This research will also improve profitability for U.S. growers and processors by increasing demand for specialty crops and by developing new value added products with high potential for export. Development of sustainable processing technologies which result in energy and water savings is another benefit of this research. Food safety will also be improved. Infrared, ultraviolet, microwave, solar thermal, forming, casting, extrusion, pasteurization and high pressure homogenization processing technologies will be explored, alone and in combination, to form novel value added food systems. Ultimately, effects of processing on final product properties will be characterized and processing methodologies optimized to maximize final product quality, safety, nutritional value, and sensory properties. An extensive network of collaborators from universities, research institutes in other countries, commodity organizations, medical research labs and the food industry, as well as sizable grants from Federal and State agencies and industry groups, will be used to support and insure a high degree of impact resulting from the research proposed in this project plan. Scientific impact will ultimately be achieved through scientific publications, patents, new mathematical models and transference of these technologies into commercialization.
Progress Report
Toward the general project objectives of developing new sustainable processing technologies to produce healthy, value-added foods from specialty crops, a USDA-NIFA-AFRI (USDA–National Institute of Food and Agriculture–Agriculture and Food Research Initiative) project on isochoric (constant-volume) freezing was initiated. The research is a collaboration between ARS researchers in Albany, California, and engineers at the University of California, Berkeley. The research team’s goal is to develop a novel freezing technology to improve the quality, nutrition, and safety of foods while reducing energy consumption during processing. Researchers completed experiments measuring the effects of isochoric freezing on cherries, spinach, fish, and tomatoes. The reported results for cherries were striking: isochoric freezing resulted in thawed fruit that were indistinguishable from fresh fruit in terms of drip loss, texture, structure, ascorbic acid content, and antioxidant activity. Reporting of the results from the other tested foods is underway.
Significant progress was made on many aspects of Objective 1. Researchers completed studies comparing the performance of electrical infrared (IR) emitters versus catalytic IR emitters for scale-up of the processing of grains. In the area of ultraviolet (UV) light in food processing, researchers determined the intensity and duration of UV-B light needed to elicit Vitamin D production in mushrooms. This work was in support of claims for a previously-filed patent.
For Objective 2, researchers continued to make significant progress on microwave and solar thermal fruit- and vegetable-processing research. Microwave-assisted extraction of valuable components from specialty crop coproduct streams was explored. The sun-drying rate of apricots was predicted from real-time measured ambient weather variables. Through a partnership, researchers tested the potential of novel solar dryers to dry tomatoes and apricots.
Significant progress was also made on all Objective 3 sub-objectives. In a partnership with local rural high school students, researchers used vacuum forming to make fruit snacks using locally-sourced pear, pomegranate, and kiwi fruit. In collaboration with researchers from Instituto Politécnico Nacional (San Isidro, Mexico), ARS researchers determined the effect of cellulose nanocrystals at three different concentrations on the microstructure of canola protein isolate edible films.
Research on legume-based snacks and beverages (Objective 4) also progressed. Effects of particle size on flavor and functionality of legume-based flours were studied. In addition, drying processes were optimized to improve the flavor and functionality of legume-based beverages made from flours.
Research continued on a wide range of cooperative research and development agreement (CRADA) projects, all of which support the objectives of the base funded research program.
Accomplishments
1. 21st-century technology makes the most out of solar drying. Solar drying of fruits and vegetables is an ancient food preservation technique, and it is still in widespread use, especially in developing countries. Sun drying is inexpensive and makes direct use of renewable energy, but it suffers from a lack of predictability and user control. To address these shortcomings and enable design of modern sun drying equipment, researchers in Albany, California, have collaborated with colleagues in both academia and industry, and this team of researchers were able to predict the drying rate of sliced nectarines based on easily-measured, real-time weather factors. It was found that solar radiation, the Temperature-Humidity-Sun-Wind index, evapotranspiration, and relative humidity had the strongest influence on the nectarines’ drying rate. These findings will help processors better predict when the fruit will be done drying and control product quality. The results of this study can be extended to other sun-dried fruits and vegetables, which are a more-than $600 million industry in the U.S. alone.
2. New freezing technology enables thawed foods with same quality as fresh. Freezing is a well-established approach for prolonging the shelf life of seasonal fruit. However, current freezing technologies (both slow and fast) result in cell damage, leading to tissue softening, irreversible turgor loss, loss of water holding capacity, and increase in drip loss during thawing. The result is a thawed product with suboptimal quality. Thus, together with colleagues at the University of California, Berkeley, ARS researchers in Albany, California, have investigated isochoric (constant-volume) freezing – a technology first developed for preservation of human organs for transplant – for not only extending the shelf life of food products, but also maintaining their physical and nutritional properties. The researchers evaluated isochoric freezing for preserving the quality of sweet cherries and found that this novel technology resulted in thawed fruit that were indistinguishable from fresh in terms of drip loss, texture, structure, ascorbic acid content, and antioxidant activity. These findings promise to disrupt the $54 billion U.S. frozen foods market, enabling products that pair extended shelf life with like-fresh taste, texture, and nutrition.
3. Legume-based gluten free extruded snacks rich in healthy bioactive compounds. Commercial gluten-free foods are generally lacking in healthy bioactive compounds. ARS researchers in Albany, California, developed novel snack-type functional foods based on extruded lentil flours that could convey the related health benefit of their bioactive compounds, provide a gluten-free alternative to consumers, and potentially increase the consumption of pulses. Extrusion treatment promoted an increase in beneficial bioactive compound content in most lentil flours. Those compounds may act as prebiotics that may convey beneficial effects to human and monogastric animals. Additionally, extrusion significantly reduced the content of antinutrients, leading to a safe and healthy food product option for consumers. The processing and product of this research could have an economical benefit to farmers and processors of pulses.
4. Low-acrylamide healthy flatbreads. Baking and frying of starchy foods induce the formation of acrylamide, which is reported to cause numerous adverse effects in humans and animals. To produce a low acrylamide and healthy baked product, ARS researchers in Albany, California, in collaboration with colleagues and industry (Simplot Company, Caldwell, Idaho) used innovative mixes of potato, quinoa, and wheat flours supplemented with health-promoting peel powders prepared from commercial fruits and vegetables (apples, cherry tomatoes, melons, oranges, pepino melons, potato, sweet potato and yams) to develop flatbreads with improved functional properties and health benefit compared to traditional flatbreads. Highly sensitive tests revealed that flatbreads made with the novel mixes had very low levels of acrylamide. Flatbreads fortified with mushroom powder also presented low acrylamide content. This research demonstrated that healthy and low-acrylamide flatbreads can be made from alternative grains, fortified with underutilized fruits and vegetable by-products. Additionally, these findings can be applied to other baked foods.
Review Publications
Vargas-Torres, A., Palma-Rodriguez, H.M., Berrios, J.D., Glenn, G.M., Salgado-Delgado, R., Olarte-Paredes, A., Prieto-Mendez, J., Hernandez-Uribe, J.P. 2017. Biodegradable baked foam made with chayotextle starch mixed with plantain flour and wood fiber. Journal of Applied Polymer Science. 134(48):45565. https://doi.org/10.1002/app.45565.
Levien-Vanier, N., Dos Santos, J.P., Villanova, F.A., Colussia, R., Elias, M.C., Pan, J., Berrios, J.D. 2018. Effects of rice amylose content and processing conditions on the quality of rice and bean-based expanded extrudates. Journal of Food Processing and Preservation. 42(9):e13758. https://doi.org/10.1111/jfpp.13758.
Milczarek, R.R., Liang, P., Wong, T., Augustine, M.P., Smith, J.L., Woods, R., Sedej, I., Olsen, C.W., Vilches, A.M., Haff, R.P., Preece, J.E., Breksa, A.P. 2019. Nondestructive determination of the astringency of pollination-variant persimmons (Diospyros kaki) using near-infrared (NIR) spectroscopy and nuclear magnetic resonance (NMR) relaxometry. Postharvest Biology and Technology. 149:50-57. https://doi.org/10.1016/j.postharvbio.2018.11.006.
Milczarek R.R., Alleyne F.S. 2017. Mathematical and computational modeling simulation of solar drying systems. In: Prakash, O., Kumar A., editors. Solar Drying Technology. Green Energy and Technology. Singapore: Springer. p. 357-379.
Watanabe, S., Matyska-Pesek, M.T., Berrios, J.D., Takeoka, G.R., Pesek, J.J. 2018. HPLC/ESI-TOF-MS identification and quantification of phenolic compounds in fermented/non-fermented Jaboticaba fruit (Myrciaria jaboticaba (Vell.) O. Berg). International Journal of Food Sciences and Nutrition. 3(5):105-109. https://doi:10.22271/food.2018.v3.i5.21.
Friedman, M. 2018. Analysis, nutrition, and health benefits of tryptophan. International Journal of Tryptophan Research. 11:1-12. https://doi.org/10.1177/1178646918802282.
