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Agricultural Experiment Station

Current Projects

These projects are also accessible through the CRIS web site of the U.S. Department of Agriculture.

Davis Dairy Plant Dryer


Drs. Clifford Hall, Padmanaban Krishnan, Srinivas Janaswamy, Brent Turnipseed, Douglas Raine

NON-TECHNICAL SUMMARY:  The USDA estimates that approximately 1 million hectares of peas, lentils, and chickpeas were harvested across 20 U.S. states in 2018. The crop value was estimated to be approximately 600 million dollars. Protein intake is an indicator of food consumption or lack thereof. Currently, and in the predicted future, protein intake will not meet dietary recommendations. Between 20 and 50 million tons of protein will be needed to fill the current production gap and meet the projected need by 2050. If pea protein were to fill just 1% of this increased demand, by 2050 this would require up to 500 million Kg of protein. The average protein content of peas is approximately 22%, thus 2.3 billion Kg of peas from an additional 1 million hectares would be needed. As a result, up to 1,000 million Kg of starch would also be generated. Thus, the utilization of this starch in food and industrial applications will be part of this assessment. The primary stakeholders for this project include pulse growers, pulse grower associations, and food manufacturers such as seed cleaners, millers, and ingredient suppliers. The interest in pulses such as pea, lentil, and chickpea is due to the nutrient composition, and the fact that these crops can be sustainably produced. The demand world-wide for plant-based protein is growing. To meet this demand, a variety of plant proteins have attracted interest by food manufacturers. Pea, lentil, and chickpea (here after referred to as pulses) will be the pulse crops targeted in this project. Fortification of cereal-based products is an ideal application of pulse ingredients because pulses are rich in folate, minerals, and lysine, an amino acid that is limiting in cereals. Furthermore, the cereal amino acids complement the amino acids in pulses, and when used in the correct proportion, produce a complete protein. However, limited data exists on the nutrient composition of dry pulses and even less data exists on the composition of pulse harvested from different locations and from pulses that have been stored under different environmental conditions (relative humidity and temperature). Furthermore, the impact of de-flavoring and other processing on composition has not been adequately address by researchers. The functionality of the stored and processed pulses also requires additional research. Research in this project will address compositional and functional attributes of pulses obtained from different growing locations, pulses stored under different environmental conditions, and pulses processed under conditions to remove bitterness and undesirable flavors. The information gained from this research will benefit pulse growers by providing them information about pulse varieties and recommendations for storage. Consumers will benefit by having available to them products that are nutrient dense, and for some individuals this would include gluten free products. Functional attributes and composition information will aid food manufacturers in developing products for consumers.

OBJECTIVES: People are aware that diet impacts health, and the message to maintain a healthy diet has been advised by dieticians for over 50 years. However, adopting and maintaining healthy eating habits are among the most difficult challenges people face. As a result, the food industry has focused in recent years on improving the nutritional quality of food products that already have high consumer acceptance. The availability of pulse-based products may contribute to combating diet-related diseases. Reports based on the National Health and Nutrition Examination Survey (NHANES) survey indicate that individuals who regularly consume pulses weigh less, have a 23% reduced risk of increased waist size, and a 22% reduced risk of being obese. A significant positive effect on body weight in individuals consuming pulse diets compared to a non-pulse control diet has been reported (Kim and Basu 2016; Shana et al. 2016). Eating pulses reduced total and LDL cholesterol levels by 5.5% and 6.6%, respectively, as compared to control diets (Bazzano et al. 2011). Data from several meta-analyses (Padhi and Ramdath 2017) supports that consumption of 2/3 cup of pulses daily lowered cardiovascular disease (CVD) risk through several mechanisms that include cholesterol reduction and reduction of other CVD biomarkers (e.g. blood pressure, inflammatory responses). Developing products with ingredients that have demonstrated health benefits, such as pulses, is one approach to prevent disease. Furthermore, a benefit is the reduction of direct and indirect cost associated with disease. Unfortunately, the direct inclusion of pulses in foods is limited due primarily to flavor and textural issues imparted by pulses in non-traditional applications. Stakeholders identified flavor issues as one of the top concerns regarding increased pulse utilization. In addition, pulse source and age have not been evaluated; thus, the impact of pulses that have been stored under various conditions should be evaluated as a contributor to undesirable pulse flavor. The age of the pulse seed may also affect nutrient composition, functionality, and shelf stability of flours or ingredients made from whole pulses. Understanding and resolving concerns related to using pulse ingredients must be addressed for pulse ingredients to be more widely used by the food industry and consumers. The goal of this project is to understand pulse flavor, functionality, and chemistry for pea, lentil, and chickpea stored under various conditions and processed to remove unwanted flavors. The project addresses needs under the Food and Non-food Products: Development, Processing, Quality, and Delivery topic area of the USDA. Data collected in this study would augment existing knowledge and encourage the food industry to develop commercial foods and foods with novel ingredients. More specifically, the project will improve our knowledge and understanding of the physical, chemical, and biological properties of foods and food ingredients. In the context of this project, pulses include dry pea, lentils, and chickpea. The overall objectives of this project include the understanding of pulse flavor chemistry and methods to mitigate the intense pulse flavor through processing, isolation, and modification of pea components and to determine the impact of pulse storage on nutrient composition and functionality. To address the utilization of dry pulses as an ingredient, the following objectives will be investigated: 1. To assess effects of de-flavoring methods on pulse flour volatile composition, sensory attributes, nutrient composition, and functionality. 2. To isolate and modify protein and starch fractions of pulses and assess the effects of modification on the chemical composition, physical properties, and functional attributes of pulse flours.  3. To characterize the changes in volatile formation, functionality, and nutrient composition of pulses stored under diverse conditions experienced during storage.

SD00H648-18. CARBOHYDRATE BASED CARRIERS OF BIOACTIVE COMPOUNDS. (October 2017 - September 2022) Dr. Srinivas Janaswamy

NON-TECHNICAL SUMMARY: Bioactive compounds (BCs) provide health benefits, especially for the prevention and treatment of chronic diseases such as diabetes, obesity, cardiovascular disease and cancer. A study on pigmented potatoes suggests that the glycemic index is significantly related to the amount of polyphenol present in the potatoes. Similarly, 24 years of research on US men and women clearly highlights the benefits of consuming foods rich in anthocyanins and dietary flavonoids to maintain a healthy weight. Furthermore, a 9-month curcumin intervention in a pre-diabetic population significantly lowered the number of pre-diabetic individuals; this suggests the beneficial role of curcumin for preventing Type 2 diabetes mellitus (T2DM). Thus, supplementation and fortification of foods with BCs are useful for maintaining good health. This concept is further supported by the recent consumer awareness and demand for healthy foods. However, incorporation of BCs in foods is a major technological challenge due to low water solubility, and instability during processing and storage. Thus, delivery of BCS through food systems is a challenge. Carriers that are compatible with the human digestive system will be a solution to effectively incorporate BCs in food and in this regard carbohydrates standout as favorable choice. Carbohydrates composed of starches and polysaccharides are staple foods and form basic energy source for humans. Carbohydrates exhibit a wide variety of unique chemical structures and physiological functions. They are capable of significantly altering texture, gelation and viscosity of aqueous based solutions, and a wide range of products can be developed using carbohydrates as functional ingredients. More importantly, they form the bulk of many foods consumed by humans and play a central role in human health. They are inexpensive; hence, their utilization for delivering BCs will not only be significant in developing health promoting and disease preventing food supplements, functional foods, and medicinal foods, but they also provide the opportunity to exploit highly used and low-cost biomaterials as value-added products. The overall objective of this project is the design and development of novel carbohydrate-based delivery systems for BCs in food, pharmaceutical and medicinal applications. The proposed research is based on the PI's hypothesis that BCs can be effectively embedded and protected in the ordered networks of carbohydrates. The hypothesis is strongly supported by the following five observations. (1) Though polysaccharides are mostly amorphous in nature, structural ordering can be achieved by preparing crystalline structures and well orienting fibers under suitable experimental conditions. (2) In the crystalline state, polysaccharides adopt stable helical structures with well-orchestrated networks stabilized by intra- and inter-helical hydrogen bonds mediated via ordered water molecules and cations. (3) In the polysaccharide network, especially in anionic samples, there are 15-25 Å wide voids often filled with water molecules, and such water pockets are amenable for embedding BCs. (4) In the case of starches, there are water channels of 16Å diameter in root starches such as potato starch that are capable of embedding BCs. (5) Starch granules such as corn starch could be treated with enzymes to create micrometer scale pores amenable for encapsulating BCs. This project will evaluate the optimal conditions for entrapment and release of BCs in carbohydrate networks (oriented fibers, starches and porous starch granules) and establish the stability and bioavailability of entrapped BCs. The loaded amounts of BCs will be determined using High Pressure Liquid Chromatography (HPLC) and UV-Vis spectroscopy. The complexes will be characterized through a series of techniques such as X-ray fiber diffraction, X-ray powder diffraction, Fourier-Transform Infrared spectroscopy, Scanning Electron Microscopy and Differential Scanning Calorimetry. The protection provided by the complexes for the BCs against digestive pH, heat, light and moisture will be established. The release rates will be determined in aqueous, simulated gastrointestinal conditions and rat studies. Overall, the outcome offers an elegant opportunity to design and develop value-added food products based on bioactive compounds that promote good health and prevent diseases.

OBJECTIVES: (1)preserve the structural form of a BC until the time of delivery, and (2) effectively deliver the preserved form to the physiological target. The following two objectives are carefully designed to provide a comprehensive evaluation of the proposed research strategy. 1. Explore the effectiveness of various carbohydrate-based carriers in encapsulating BCs 2. Assess the stability and bioavailability of encapsulated BCs.


NON-TECHNICAL SUMMARY: Enhancing the microbial quality and safety of milk and dairy products is an ongoing challenge. As a result of ever changing processing technologies and emerging issues related to spoilage and disease causing microorganisms, effective and efficient control of bacteria in dairy processes is critical if U.S. dairy products are to compete in the multi-billion dollar global export market. Some sporeformers and endospores resist thermal treatments and are primarily responsible for spoilage of milk and dairy products. It is thus imperative to find process interventions to control their proliferation. Our previous research in this area demonstrated hydrodynamic cavitation as a process that can be combined with pasteurization to inactivate thermoduric sporeformers and their spores. Further research in this area can help us scale-up this process, and at the same time identify processing conditions that will influence the sporulation and spore germination behavior of common dairy sporeformers. This will help the dairy industry reduce the adverse effects of sporeformers and manufacture products that can easily compete in global markets. Another important aspect related to dairy products is safety. Several incidences of food poisoning have affected the credibility of dairy products as wholesome for consumers, and resulted in serious economic consequences. For example a recent large outbreak involving Listeria monocytogenes in ice cream resulted in major recalls and shut down ice cream manufacturing facilities for several months. The persistence of Listeria;in dairy processing environments, and ability to cross-contaminate ice cream is not clearly understood. We propose to conduct challenge studies in simulated ice cream manufacturing processes to generate response surface models to predict risk more accurately. This will help us design more robust hazard analysis and risk-based preventive controls (HARPC) for preventing food pathogens such as Listeria. The project will be conducted in collaboration with industrial partners to generate risk models directly applicable under field conditions. The information generated will help the dairy industry prevent food borne outbreaks.Improving the nutritional value of dairy ingredients, especially by designing new products and formulations, is the next thrust area identified by US dairy industry. Probiotic applications will play a significant role in this attempt due to increased consumer acceptance and growth in this sector of fermented dairy products. At the same time, value added byproducts such as whey protein isolates and concentrates provide additional avenues for developing health products. We plan to develop an encapsulated probiotic product using whey protein hydrolysates as encapsulants. Such a product will have the recognized health benefits of both whey proteins and active probiotic cultures. This will provide the dairy industry with another novel dairy product in the healthy products portfolio.

OBJECTIVES: Goal 1: To improve microbial quality and shelf life of milk and dairy products

Objective 1.1: To understand sporulation behavior of common sporeformers during milk powder manufacture Objective 1.2: To apply non-thermal technologies, such as cavitation, to control common dairy spore formers.

Goal 2: To improve microbial safety of dairy processes.

Objective 2.1: To control dairy pathogens such as Listeria by risk analysis, through response surface models.

Goal 3. To develop novel dairy products containing probiotics. 

Objective 3.1: To develop a spray-dried health formulation based on whey protein hydrolysate and probiotics encapsulation.