Location: Healthy Processed Foods Research
2016 Annual Report
Objectives
The long-term goal of this project is to develop novel methods, and define measure and mitigate attributes that adversely impact the quality of foods. Specifically, during the next five years we will focus on the following objectives:
Objective 1: Enable novel commercial methods for prevention or removal of defects and contaminants in foods.
• Subobjective 1A: Develop techniques for detection and removal of potatoes affected by Zebra Chip disorder from the processing line.
• Subobjective 1B: Develop X-ray based alternatives to radioisotopes for irradiation.
Objective 2: Integrate physical, chemical, sensory, and biological changes from raw and commercially processed food products, including, olives and grapes.
• Subobjective 2A: Pinpoint and identify impact aroma compounds of raw materials and commercially processed products from specialty crops including grapes and olives using gas chromatography-olfactometry (GC-O) and gas chromatography-mass spectrometry (GC-MS). Identify precursors (and eventually pathways) of such impact aroma compounds and study flavor variation in different varieties.
• Subobjective 2B: Isolate and characterize phytonutrients in raw materials and food products from grapes, olives, and other specialty crops. Determine the effects of processing on the levels of these constituents and also monitor changes in biological activity (i.e., antioxidant activity).
Objective 3: Integrate measurable allergenic properties with methods to mitigate food allergens in nuts and dairy.
• Subobjective 3A: Identify, characterize, and develop methods for the detection of food allergens in tree nut and other foods.
• Subobjective 3B: Investigate and differentiate allergen cross-reactivity and multi-sensitization and study the effects of processing methodologies on allergenicity.
Approach
1A: Acquire x-ray images and NIR spectra from whole potatoes (reflection) and through slices (transmission). Analyze slices for moisture and sugar, followed by frying and color evaluation. Develop calibration equations for prediction of Zebra Chip (ZC), moisture content, sucrose, and glucose and investigate correlations between ZC and moisture and/or sugar. Isolate appropriate subsets of NIR absorbance values as input features for standard statistical classification techniques. Test appropriate optics that can measure absorption at the determined wavelengths for the ability to evaluate ZC. Observe x-ray images for differences between potato classes and develop detection algorithms. 1B: Design, build, and test x-ray based irradiation units was alternatives to traditional gamma based units using two technologies: traditional x-ray tubes and a higher power prototype x-ray emitter system.
2A: Extract aroma compounds from grapes and olives using GC. Identify precursors and study flavor variation in plant varieties. Have judges evaluate ability to detect odor from each compound’s effluent from a GC column, with compounds detected in the most dilute sample considered to be impact aroma compounds. Identify acquired capillary GC-MS spectra using established libraries to identify food constituents. Quantify food constituents by GC-MS by comparing the areas of characteristic mass fragment ions of the compounds with that of 2-undecanone (m/z 170). Calculate odor activity values by dividing the determined concentrations by their odor thresholds. For confirmation, compare synthetic blends of identified odorants with those of the original raw and processed products using sensory panels.
2B: Extract homogenates from processed and unprocessed food components and analyze using an HPLC-diode array detector. Identify constituents by comparison of retention times and UV/Vis spectra of unknown peaks with those of authentic standards and verify by HPLC-MS, NMR or IR if necessary. Determine weight and total phenolic content for each homogenate. Evaluate antioxidant activity by the DPPH and ABTS procedures. Determine effects of processing by comparison.
3A: Isolate 2S albumins from nuts and express recombinantly to assess their allergenicity using sera from allergic patients. Isolate and express profilin protein for comparative studies. Develop protocols to purify 2S albumin allergens in other nuts including almond, pine nut, coconut, macadamia nut, and optionally chestnut. Determine the peptide sequences by N-terminal peptide sequencing and mass spectrometry. Develop antibody based methods for detecting food allergen and allergic food.
3B: Isolate and clone hazelnut allergens following established protocols. Assay association with serum IgE from patients known to react to peanut and/or hazelnut. Frequency of IgE recognition of allergens will reflect cross-reactivity and multi-sensitization. Process samples by extrusion to investigate processing effects on allergenicity.
Progress Report
Sub Objective 1A: Near infrared (NIR) spectra of 400 potatoes (half with Zebra Chip (ZC) disorder) have been obtained and High Performance Liquid Chromatography (HPLC) base sugar analysis was performed on each. Preliminary classification results yield very high accuracy (>95%) in identifying affected potatoes based on chemometric analysis of the entire spectra. More sophisticated statistical analysis to reduce the number of required wavelengths are underway, as is the correlation analysis between ZC and sugar content. The preliminary results indicate a high likelihood that NIR based detection of the disorder is feasible.
Sub Objective 1B: X-ray tube based irradiation units have been constructed and their efficacy as a suitable replacement to gamma irradiation for insect sterilization has been demonstrated. The x-ray emitter system is operational and x-ray dose experiments are underway.
Sub Objective 2A/2B: Flavor has the greatest impact on consumer acceptability of black-ripe table olives. Flavor is related to the qualitative and quantitative composition of volatiles that influence the quality of table olives. Aroma constituents of different varieties of table olives (including Ascolano, Kalamata, and Picual) were isolated using dynamic headspace sampling and analyzed by gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS). This information will be useful in identifying flavor differences among olive varieties and in determining the contribution of individual volatiles to the overall aroma. This research relates to Subobjective 2A which involves the identification of impact aroma compounds in commercially produced products from specialty crops including olives.
Sub Objective 3A/3B: For Objective 3, we have developed respective protocols for purifying profilin from tree nuts. We also made significant progress in constructing expression plasmid for recombinant production of the tree nut profilin allergens. We obtained, from a commercial source and from our collaborators, sera from patients allergic to peanuts and tree nuts (e.g., walnut and pecan). These reagents were used for to identify new food allergens in nuts. They are also being used to assess the relative importance of linear and conformational IgE epitopes in peanut allergy (a representative of persistent allergy) and in milk allergy (which is mostly a childhood allergy). They will also be used in investigating the importance of multi-sensitization and cross-reactivity in food allergies.
Accomplishments
1. Near infrared (NIR) based detection of pits in cherries. High speed sorting of cherries to remove pits that were missed by the pitting machine is a high priority research area for the industry. Agricultural Research Service (ARS) researchers in Albany, California have used NIR spectroscopy to identify pits in cherries with accuracy greater than 99%. Furthermore, data reduction to reduce the number of required wavelengths maintained the classification accuracy at greater than 95%. This provides the means to construct optical sorting devices based on reflection of light from a limited set of wavelengths that can detect pits at high speed, thus reducing the potential for injury to consumers and subsequent litigation.
2. Near Infrared (NIR) based detection of Zebra Chip disease in potatoes. Zebra Chip disease causes discoloration of potatoes upon frying in a pattern resembling stripes on a zebra. The disease has become an economically important disease of potatoes in the U.S. ARS scientists in Albany, California have demonstrated the efficacy of NIR spectroscopy to non-destructively identify the disease with high accuracy. This provides the means to construct optical sorting devices based on reflection of light from a limited set of wavelengths that can detect Zebra Chip disease at high speed, thus removing them from the processing stream and preventing diseased potatoes from reaching the marketplace.
3. A new pecan allergen officially identified. Tree nut (including pecan) allergies are equally as common and dangerous as peanut allergies, affecting millions of Americans and negatively impacting tree nut utilization. Thus, there is an urgent need to define, measure, and mitigate the allergenicity of tree nut (as well as other food) allergens. ARS researchers at Albany, California and their collaborators have identified a new pecan allergen which is now officially designated as Car i 2 by the World Health Organization and International Union of Immunological Societies Allergen Nomenclature Sub-committee. The identification and characterization of this allergen increases understanding of the allergenicity of pecan, walnut, and other foods, critical for the development of treatments and/or cures for devastating allergies worldwide.
4. Quantification of toxic amino acids in soapberry fruit. Consumption of certain soapberry fruit such as ackee and litchi can induce hypoglycemia, encephalopathy and even death. Albany, California scientists recently confirmed that recurring outbreaks of acute hypoglycemic encephalopathy are associated with the deaths of hundreds of children each year in India of litchi consumption. The causative agents in soapberry fruits are the toxic cyclopropyl amino acids, methylenecyclopropylglycine (MCPG) and hypoglycin A (HGA). A method to simultaneously quantify both MCPG and HGA from 1 to 10,000 ppm in dried soapberry fruit has been developed, and, HGA has been identified and quantified for the first time in litchi. This method can be used to identify and quantify MCPG and HGA in other soapberry fruits, providing knowledge with the potential to prevent or reduce future deadly outbreaks.
5. New uses for pomegranate peels. Pomegranates are an important medicinal and nutritional product, with potential for prevention of cancer and cardiovascular diseases. Pomegranate peels constitute up to 40% of the whole fruit and are a by-product of juice production. To evaluate their potential as a functional food ingredient, the phenolic composition of five varieties (Molla Nepes, Parfianka, Purple Heart, Wonderful and Vkunsyi) of pomegranate peel has been determined by researchers in Albany, California. The Vkunsyi cultivar had the highest concentrations of gallic acid, catechin and the desirable ellagitannin punicalagin. This cultivar is a potentially rich source of desirable phenolic compounds, indicating that this waste product is a potential additive to increase the healthfulness of foods.
None.
Review Publications
Haff, R.P., Jackson, E.S., Gomez, J., Light, D.M., Follett, P.A., Simmons, G.S., Higbee, B.S. 2015. Building lab-scale x-ray tube based irradiators. Journal of Radiation Physics and Chemistry. 121:43-49.
Haff, R.P., Jackson, E.S., Moscetti, R., Massantini, R. 2015. Detection of fruit-fly infestation in olives using X-ray imaging: Algorithm development and prospects. American Journal of Agricultural Science and Technology. 4(1):1-8.
Stella, E., Moscetti, R., Haff, R.P., Contini, M., Cecchini, M. 2015. Recent advances in the use of non-destructive near infrared spectroscopy on intact olive fruits. Journal of Near Infrared Spectroscopy. 23:197-208.
Stella, E., Moscetti, R., Massantini, R., Monarca, D., Cecchini, M., Haff, R.P., Contini, M. 2015. Recent advances in the use of NIR spectroscopy for qualitative control and protection of extra virgin olive oil. La Rivista Italiana Delle Sostanze Grasse. XCII:155-173.
Sedej, I., Milczarek, R.R., Wang, S., Sheng, R., Avena Bustillos, R.D., Takeoka, G.R., Dao, L.T. 2016. Membrane-filtered olive mill wastewater: Quality assessment of the dried phenolic-rich fraction. Journal of Food Science. 81:E889–E896. doi: 10.1111/1750-3841.13267.
Moscetti, R., Haff, R.P., Stella, E., Contini, M., Monarca, D., Cecchini, M., Massantini, R. 2014. Feasibility of NIR Spectroscopy to detect olive fruit infested by Bactrocera oleae. Postharvest Biology and Technology. 99:58-62.
Moscetti, R., Haff, R.P., Monarca, D., Cecchini, M., Massantini, R. 2016. Near-infrared spectroscopy for detection of hailstorm damage on olive fruit. Postharvest Biology and Technology. 120:204-212.
Sedej, I., Milczarek, R.R., Wang, S., Sheng, R., Avena Bustillos, R.D., Takeoka, G.R., Dao, L.T. 2015. Spray drying of a phenolic-rich membrane filtration fraction of olive mill wastewater: Optimization and dried product quality. International Journal of Food Science and Technology. doi: 10.1111/ijfs.13163.
Zhang, Y., Lee, B., Du, W., Fan, Y., Lyu, S.C., Nadeau, K.C., Grauke, L.J., Zhang, Y., Wang, S., Mchugh, T.H. 2016. Identification and characterization of a new pecan [Cara illinoinensis (Wangenh.) K. Koch] allergen, Car i 2. Journal of Agricultural and Food Chemistry. 64:4146-4151.
Yi, J., Fan, Y., Zhang, Y., Wen, Z., Zhao, L. 2016. Glycosylated a-lactalbumin-based nanocomplex for curcumin: physicochemical stability and DPPH-scavenging activity. Food Hydrocolloids Journal. 61:369-377.
Shen, Q., Zhang, Y., Yang, R., Hua, X., Zhang, W., Zhao, W. 2015. Thermostability enhancement of cellobiose 2-epimerase from Caldicellulosiruptor saccharolyticus by site-directed mutagenesis. Journal of Molecular Catalysis B: Enzymatic. 120:158-164.
Fan, Y., Hua, X., Zhang, Y., Feng, Y., Shen, Q., Dong, J., Zhao, W., Zhang, W., Jin, Z., Yang, R. 2015. Cloning, expression and structural stability of a cold-adapted ß-Galactosidase from Rahnella sp.R3. Protein Expression and Purification. 115:158-164.
Fan, Y., Hua, X., Jin, T., Feng, Y., Yang, R., Zhang, Y. 2016. Structural analysis of a glycosides hydrolase family 42 cold-adapted ß-galactosidase from Rahnella sp. R3. RSC Advances. 6(44):37362-37369. doi: 10.1039/C6RA04529D.
