Location: Healthy Processed Foods Research
2019 Annual Report
Objectives
The overall goal of this research project is to make food production more sustainable by using food processing technologies to add value to the byproducts generated from the harvest of specialty crops and production of processed foods. We will focus on the following three objectives over the next five years:
Objective 1: Increase the commercial value of plant-based, postharvest waste materials, high in dietary fiber and/or polyphenols (grape, berries, tomato, carrot, and olive pomace, olive leaves and water, mushroom byproducts), by reprocessing into healthful food ingredients.
1.1: Screen processing wastes for nutritional properties of the whole pomace, seeds, skins, and the extractable and nonextractable (high fiber) fractions using appropriate animal models.
1.2: Increase value by developing healthful ingredients with improved bioaccessibility to bioactive polyphenols by process treatments such as extrusion, thermal, chemical and enzymatic processing of the whole waste.
Objective 2: Enable new, commercial functional foods from high protein–based waste materials (nuts, legumes, rice, fish).
2.1: Analyze nutrient content of processed farm waste (soybean, peanut, rice and salmon) for functional properties and nutritional quality of protein fraction.
2.2: Formulate and test high protein gluten free health promoting products for consumer acceptability.
Objective 3: Enable value-added commercial applications of nanofibers from specialty crop waste materials to deliver bioactives in new functional foods.
Objective 4: Increase the utilization of post-harvest waste materials by identifying and removing astringent and mineral components that detract from taste, quality, nutritional value and consumer acceptance.
Approach
Objective 1: Determine if processed food wastes or their components from regional fruit and vegetable food processing have health promoting properties by using animal models of obesity and related metabolic diseases to evaluate bioactivity. Animal models are necessary since many bioactive compounds are not absorbed directly but are mediated by gut bacteria. Some waste materials may require fractionation, for example seeds from peels, in order to concentrate bioactive components to a useful level. Bioavailability and bioactivity of more bioactive compounds such as polyphenolics and plant sterols may be increased by removing and modifying dietary fibers that block accessibility to enzymes and gut bacteria. Bioactive food wastes such as mushrooms with high vitamin D content will be processed into films or coatings.
Objective 2: Develop new healthy and flavorful foods from high protein waste materials. Processing wastes from soybeans, peanuts, rice and salmon will be analyzed for protein composition and food related physico-chemical properties. The waste materials will be formulated into foods to increase protein content and improve protein quality. Waste ingredients are often high in insoluble fibers that reduce functionality and may require fractionation from fiber to improve useful properties.
Objective 3: Develop blow spinning technology to efficiently produce natural nanofibers for controlled release applications and evaluate potential pulmonary toxicity effects of nanofibers in mice after intratracheal instillation of nanofibers. Using blow spinning processes nanofibers will be created from food ingredients such as gelatin, chitosan, and fruit and vegetable pomaces (grape, carrot, tomato and olive) in order to eliminate or reduce potential inhalation inflammation or toxicity. Although the nanofibers will be used for encapsulation of bioactive compounds for oral delivery the potential for inhalation during process requires toxicity testing. The ingredients as well as the nanofibers will be evaluated for inflammation and toxicity in a mouse model to determine degree and persistence of inflammation or toxicity if any. Ingredients that are most biocompatible will be used in subsequent studies.
Objective 4: Develop strategies to mitigate astringency in post-harvest materials in order to increase their utilization. Tannins and minerals contribute to astringency and the identification and characterization of these components is essential. Total and free mineral contents in waste materials (nut shells, hulls, pits, pomaces, skins and seeds from stone fruits, nuts, and persimmons) will be measured using microwave-induced plasma atomic emission spectrometry following microwave-assisted digestion or leaching. Tannin levels in the same materials will be measured using total soluble phenolic, potassium iodate (hydrolysable tannin), and vanillin (condensed tannin) assays. The metal (Zn, Cu, Fe) and protein binding properties of waste material tannins will be measured and compared to the properties of commercially available tannins.
Progress Report
In support of Sub-objective 1.1, research continued on determining potential health promoting effects of byproducts of food processing of two new sources: pomegranate peels from juice processing and grain byproducts of beer processing. Hamsters on high fat diets supplemented with pomegranate peels and ethanol extract of peels had higher levels of plasma cholesterol. Expression of genes involved in cholesterol and fat metabolism in the liver are being analyzed in order to understand the molecular basis for the differences in cholesterol. Mice fed high fat diets supplemented with 10, 20, and 40 percent byproducts of beer processing had decreased weight gain with increasing byproduct content. Increasing the beer byproduct decreased caloric density. Usually, animals will adjust their daily food intake to consume the same number of calories. Surprisingly, the food intake was similar between 0, 10, 20, and 40 percent beer byproduct diets, suggesting a satiation effect of the fiber and/or protein content.
There is increased interest in fermented foods, possibly due to the importance of probiotics. In collaboration with a visiting scholar from China, we also evaluated a mixture of food herbs used in Chinese tea. The tea ingredients were fermented by a bacterium isolated from the human gut and fed to an animal model of obesity and metabolic dysfunction. In mice on high fat diets, the fermented tea reduced body weight but did not affect liver or adipose weights compared to the high fat control and the unfermented tea. Importantly, both the unfermented and fermented teas improved glucose metabolism, as evidenced by improved glucose tolerance test, suggesting this drink may prevent insulin resistance and diabetes. A manuscript is in progress.
In support of Sub-objective 1.2, fiber and indigestible phytochemicals, such as polyphenolics, are the major components and major bioactive components of byproducts of food processing. Legumes are low in fat and contain high amounts of dietary fiber and some, such as black beans, also contain polyphenolics. Whole black beans, the seed coat and the endosperm were fed to mice on high fat diets. The whole beans had the most physiological effects and lowered very low- and low-density lipoprotein cholesterol. These cholesterol particles are risk factors for cardiovascular disease. The bean diet also improved insulin sensitivity and reduced blood glucose, suggesting that they may help to prevent insulin resistance and diabetes. Leptin, a hormone secreted by fat cells, was also decreased by the whole bean diet. Leptin decreases appetite; however, in obese individuals blood leptin levels are much higher than in normal weight individuals due to decreased sensitivity to leptin. Glucagon, a hormone secreted by the pancreas, was also lowered by the whole bean diet. Glucagon decreases blood glucose and is consistent with lower blood glucose found in this study.
Additional research also in support of Sub-objective 1.2, focused on the cellular and extracellular sources of healthful properties of probiotic bacteria and the results were published. Meanwhile, research continued on the healthful properties of food processing waste from wine processing, apple juice processing, potato processing, and other foods. As well, a large Binational Agricultural Research and Development Fund grant helped support studies in which the bioactive food wastes from mushrooms with high vitamin D content were processed into coatings for fruit bars and cantaloupe. In related research, ARS scientists also published a scientific journal article reporting that heat-killed bacteria from a fermented milk product and its external polysaccharide coating both reduced weight gain and other undesirable metabolic effects in mice on high fat diets. A scientific article was also published reporting that potato skins from colored potatoes reduced fat deposits in mice on high fat diets. As well, collaborative research under a Cooperative Research and Development Agreement (CRADA) continued to investigate value-added food applications for brewers spent grains. Research was completed on processing of the brewers spent grains to ensure safety and increase stability in support of commercialization of this new healthy food ingredient. This research was awarded a Small Business Innovation Research (SBIR) grant.
Snack foods are often low in protein. Therefore, the composition of gluten-free whole grains, buckwheat, quinoa, peanut meal, kale and beets and prepared snacks were determined in relation to developing more nutritious snack foods in support of Sub-objective 2.2. The sensory properties of whole grain gluten-free buckwheat, peanut meal, and kale snacks were evaluated and found to be satisfactory to consumers.
In support of Sub-objective 3, blow spinning technology was used to efficiently produce natural nanofibers for controlled release applications from gelatin and corn zein. Natural antimicrobials were incorporated into these nanofibers and controlled release properties were studied. In addition, safety studies of the nanofibers were completed.
In regards to Sub-objective 4, research on astringency of persimmons was completed and effects of different varieties and postharvest drying on persimmon quality were studied.
Accomplishments
1. Black beans prevent insulin resistance and improve blood glucose control. Obesity in the U.S. is a major public health concern because obesity increases the risk of diabetes, cardiovascular disease, fatty liver disease, hypertension, and some cancers. Black beans are low in fat, and high in dietary fiber and polyphenolic compounds. Polyphenolics are bioactive compounds that have been shown to reduce blood pressure in humans and animals, and reduce weight gain and blood lipids in animal models of obesity. ARS researchers in Albany, California, showed in animal models that black beans prevent insulin resistance, a precursor to diabetes, and improve blood glucose control. Beans also reduced leptin, a hormone found in higher levels in obese individuals.
Review Publications
Chen, L., Liang, R., Wang, Y., Yokoyama, W.H., Chen, M. 2018. Characterizations on the stability and release properties of ß ionone loaded thermosensitive liposomes (TSLs). Journal of Agriculture and Food Sciences. 66(31):8336-8345. https://doi.org/10.1021/acs.jafc.7b06130.
Li, Y., Ding, G., Yokoyama, W.H., Zhong, F. 2017. Characteristics of annealed glutinous rice flour and its formation of fast-frozen dumplings. Journal of Cereal Science. 79:106-112. https://doi.org/10.1016/j.jcs.2017.09.016.
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., Larson, D., Li, Y., Sedej, I., Wang, S. 2019. Olive. In: Pan, Z., Zhang, R., Zicari, S., editors. Integrated Processing Technologies for Food and Agricultural By-Products. 1st Edition. San Diego, CA: Elsevier Inc. p. 355-371. https://doi.org/10.1016/B978-0-12-814138-0.00014-9.
Milczarek, R.R., Woods, R., LaFond, S.I., Breksa, A.P., Preece, J.E., Smith, J., Sedej, I., Olsen, C.W., Vilches, A.M. 2017. Synthesis of descriptive sensory attributes and hedonic rankings of dried persimmon (Diospyros kaki sp.). Food Science and Nutrition. 6(1):124-136. https://doi.org/10.1002/fsn3.537.
Crawford, L.M., Kahlon, T.S., Chiu, M.M., Wang, S.C., Friedman, M. 2019. Acrylamide content of experimental and commercial flatbreads. Journal of Food Science. 84(3):659-666. https://doi.org/10.1111/1750-3841.14456.
Fan, Y., Gao, L., Yi, J., Zhang, Y., Yokoyama, W.H. 2017. Development of ß-carotene-loaded organogel-based nanoemulsion with improved in vitro and in vivo bioaccessibility. Journal of Agricultural and Food Chemistry. 65(30):6188-6194. https://doi.org/10.1021/acs.jafc.7b02125.
