Performing Department
Horticulture and Landscape Architecture
Non Technical Summary
Colorado is known for specialty cultivars such as Purple Majesty and Masquerade and many other colored flesh verities. Purple Majesty is a purple flesh potato known to have comparable antioxidant properties with fruits such as pomegranate and blueberries by serving size. Masquerade, a newly released cultivar, has shown excellent culinary and flavor qualities. The major weakness for these specialty varieties is their short duration of natural dormancy.Coatings are used to improve appearance or texture and reduce water loss. There are some advantages when a coating is applied to fruits and vegetables. Shelf life can be extended by coating products. The coating can reduce desiccation and oxidation by creating a modified atmosphere around coated products. Formulations can be designed to carry desired additives that help to extend product stability and, therefore, shelf life, encapsulate flavor during storage and improve mechanical handling properties by helping fruit slip over packing lines with less injury.The sensory and biochemical composition of fruits and vegetables are essential to the increasingly health-conscious consumer. In the case of chile peppers, some retail outlets (Whole Foods) are requiring nutritional information on packaging. Further, pungency or heat is often the primary characteristic that drives consumer choices. This project will enable Colorado-growers to advertise important flavor and nutritional properties of their produce. Methods to extend the product shelf life will help to reach distant markets.Capsaicinoids possess strong physiological and pharmacological activities. The medicinal value of capsaicin has been evaluated in the treatment of painful conditions such as rheumatic diseases, cluster headaches, painful diabetic neuropathy, and post-herpetic neuralgia. Even consumed in low amounts in the diet, capsaicinoids decrease the myocardial and aortic cholesterol levels. The consumption of hot peppers is mainly due to their pungent flavor and is determined by the production of capsaicinoids within the pod. Capsaicinoids are alkaloid compounds that produce the hot flavor or pungency associated with eating chilies. Quantification of these pungent compounds is an important index of hot pepper quality and subsequently, an extremely important marketing tool. The degree of pungency in pepper depends on several environmental and genetic factors. Accurate measurement of pungency has become important because of increased consumer awareness of the flavor profiles in their food. In addition, the accurate determination of capsaicinoid levels is needed due to their growing use in the pharmaceutical industry.Melons have great diversity in their size, shape, flesh and rind color. Diversity is also found in the array of physical and chemical characteristics (i.e., sugars, flavors, texture, aroma, and nutrient content) that collectively define a melon's quality. Overall, both genetics and growing environment play significant roles in determining a melon's physical attributes, composition, and flavor. Melons have a short harvest window and postharvest shelf life. One possible strategy to counter this problem lies in extending the harvest window and improving the post-harvest stability of melons. The recent introduction of Long-Shelf- Life (LSL) melons represents a significant breakthrough in addressing the aforementioned issues; however, even less is known about the physical and chemical characteristics of LSL varieties as compared to popular varieties now grown in the Rocky Ford region. The type and content of soluble sugars and organic acids determine the organoleptic properties of fruits. Soluble sugars in fruits include fructose, glucose, and sucrose. Malic-, citric-, and oxalic acids are the primary organic acids. Soluble sugars, organic acids, and aroma are essential components of fruit flavor and have a substantial impact on overall organoleptic fruit quality.
Animal Health Component
40%
Research Effort Categories
Basic
40%
Applied
40%
Developmental
20%
Goals / Objectives
The postharvest research program at the San Luis Valley Research Center is designed to address some of the issues faced by the potato growers related to storage management, tuber quality, nutritional aspects, and physiological disorders during storage. In addition to this my research program also works with other vegetable and fruit industry in postharvest aspects to increase their marketability by extending shelf life in the case of peppers and melons.Goal 1: The primary goal of our program is reducing shrink in potato storage. The goal of potato storage is to maintain the quality and quantity of marketable tubers throughout the storage period in order to maximize economic returns. Clearly, profitability is tightly linked to both tuber quality and mass loss (shrinkage). The most important issue during potato storage, beside spoilage, is the weight loss.Objectives are:To extend dormancy with coatings along with a sprout inhibition in the specialty cultivarsTo reduce weight loss in storage and other associated storage disordersGoal 2: The purpose of this project is to facilitate the growth of the Colorado pepper industry by identifying the pungency and nutrient composition of Colorado-grown peppers. This project will examine standard pepper varieties grown in Colorado as well as novel varieties developed by the Colorado State University pepper breeding program.Objectives are:Determine the pungency (Scoville Heat Units) of Colorado-grown peppers.Characterize the nutritional characteristics of Colorado pepper cultivarsStudy methods to extend the shelf life of specialty pepper cultivars to increase marketabilityGoal 3: Melons have a very short (1-2 days) harvest window that dramatically affects the quality and post-harvest shelf life. If a melon is not harvested within the optimum window, it is unmarketable.Objectives are:Characterizing popular varieties grown in Rocky Ford area as what defines as for Rocky Ford melonsDetermining how variety, state of maturity, and post-harvest handling influence melon shelf life, sensory attributes, and ultimate marketability
Project Methods
1. Weight loss, nutritional composition and shelf life of potato tubers are a major concern in the long-term potato storage. Edible coatings are used in fruits and vegetables to improve appearance, texture, reduce water loss, quality, and economic returns. In this study, we will investigate zein formulation (10% w/v), potato starch formulation (2% w/v), and isolated soy protein formulation (2.5% w/v) as potential edible coatings on potato tubers in three different cultivars: Yukon Gold, Purple Majesty, and Rio Grande Russet before putting them in storage. During storage, we will monitor the respiration rate, weight loss, and disease and their effect on the nutritional composition. Preliminary studies showed a promising effect in reducing weight loss in low relative humidity (RH) (50%) level compared to high RH (92%) level.2. In this study, the freeze-dried material of peppers will be ground to a fine powder. Thereafter, polyphenolic compounds, vitamin C, and other nutritionally important compounds will be identified and characterized. We will use a variety of analytical techniques including HPLC and other chromatography methodologies. Samples will be collected from the Arkansas Valley Research Center test plots and from area growers. This project will be conducted in collaboration with Dr. Bartolo in the Arkansas Valley Research Center.3. The purpose of this project, therefore, is to characterize the physical and chemical nature of existing varieties of Rocky Ford melons as well as new LSL types. In addition, the project will determine how variety, state of maturity, and post-harvest handling influence melon shelf life, sensory attributes, and ultimate marketability.In the second phase, popular commercial varieties will be selected within each market class (Galia or cantaloupe). These will be grown at the Arkansas Valley Research Center under typical field conditions (plastic mulch, drip irrigation, etc.), with entries replicated and randomized. At maturity, each variety will be harvested and tested. Photographs will be taken of each variety at harvest and an evaluation. Sufficient numbers of fruit will be harvested for each variety to allow weekly testing from each replicate of each variety in each treatment over the course of the three-week storage period.Current popular varieties in Rocky Ford area will be grown at Arkansas Valley Research Center and will be evaluated for the characteristics that define them as Rocky Ford melons. A number of promising varieties will be selected based on the published available literature and grown at Arkansas Valley Research Center. Fruits will be harvested at different maturity stages. External appearance (rating scale will be used developed by UC Davis), Flesh firmness: Measured in psi using a penetrometer Brix: Brix measurements are based on at least 3 fully ripe fruit per variety, and 3 samples per fruit and ethylene will be measured to measure the stage of ripeness. The color of the rind will be measured based on the 1-5 scale, 5 being the desired color. Three pieces from each melon will be frozen to determine flavor compounds.