Location: Methods and Application of Food Composition Laboratory
2019 Annual Report
Objectives
Objective 1. Determine the impact of industrial packaging methods (canning, freezing and drying) on the nutrients and bioactive compounds in fresh fruits and vegetables.
Objective 2. Validate a software program based on mathematical optimization techniques for estimating nutrient contents of commercial multi-ingredient foods.
Objective 3. Determine the impact of dietary fiber methodology on fiber composition and intake estimates.
Approach
Objective 1. Industrial processing alters nutrients/bioactive compounds in fruits and vegetables. A 2-step, 2-year study for sample collection will be conducted. Consulting USDA plant scientists/other collaborators, multiple same-cultivar ripe samples will be collected simultaneously from one. Samples will be analyzed for vitamins, fiber, minerals, polyphenols, and metabolomics (baseline). Portions will be transported and stored to emulate typical commercial storage conditions; nutrients/polyphenols will be conducted in stored raw samples every 3 days until they decay. Shipping practices for samples will be simulated through collaborations with processing plants near harvest locations, emulating agricultural and industrial practices. Analyses at 0, 14, 35, 70, 120, 180 and 360 days post processing, and analysis in validated commercial laboratories, using AOAC methods, polyphenolic compounds analysis by ARS/academic collaborators will address the impact of processing.
Objective 2. Linear programming software for estimating missing nutrient values in commercially processed foods (using label values, ingredient lists) requires improved automation and analytical ingredient data. Food types (e.g., baked products) and nutrients will be identified, program functionality improvements completed, and tests, where ingredient proportions and nutrient values are known, will allow determination of estimation accuracy. The Virginia Tech (VT) Food Analysis Laboratory Control Center will prepare foods and QC materials for analysis; food manufacturers will be consulted on ingredient proportions, and an equivalence study of the estimates will be conducted to determine classes of nutrients and food types where the estimated and analytical values are similar, i.e. within ± 20%. Program validation will ensue to assess which nutrients to include.
Objective 3. The McCleary method (MCF) is a more complete determination of dietary fiber (DF) content in foods compared to the enzymatic-gravimetric (EGF) method, enabling better intake estimates. Select high-fiber foods and frequently consumed, fiber-containing foods will be analyzed by EGF (985.29) and MCF (2011.25) methods at a USDA-qualified commercial analytical lab. Foods with isolated or synthetic non-digestible carbohydrates may be analyzed. EGF (AOAC 985.29; total DF) and EGF (AOAC 991.43; soluble and insoluble DF), and MCF (AOAC 2009.01 and 2011.25 (fractions) will be studied and summed. Sumswill determine the food types where the fiber method used does not make a difference for measuring total DF. This allowsbetter understanding of the effect of fiber methodologies for selecting the appropriate analytical method for specific foods.
Progress Report
Objective 1. Determine the impact of industrial packaging methods (canning, freezing and drying) on the nutrients and bioactive compounds in fresh fruits and vegetables. Local corn growers were contacted and identified. Selected yellow corn at different harvest times were collected and processed for a pilot study.
Foundation Foods - eggs sampled in 24 nationally representative US locations and oils sampled in Maryland and Virginia (olive, canola, corn, vegetable (soybean)) will be sent to analytical labs for analysis FY19. Bananas were studied at Vermont (local samples) for carbohydrate profiles and degree of ripeness.
Objective 2. Validate a software program based on mathematical optimization techniques for estimating nutrient contents of multi-ingredient foods.
Ingredient lists for 70-80% of the baked products sold by weight in the U.S. were obtained using the Global Branded Food Product Database and manufacturer’s websites. These lists were parsed to identify individual ingredients and then reviewed to identify highly used commercial ingredients for which good quality analytical data are needed. The results were shared at professional conferences.
Objective 3. Determine the impact of dietary fiber methodology on fiber composition and intake estimates. Collaborations were established. Bananas, were sampled and analyzed to investigate how ripeness stage and/or domestic cooking affect fiber structures and contents.
Additional Research: Iodine. Foods high in iodine were analyzed and merged with FDA analytical data to develop multi-agency database on iodine in US foods. Mapping to reported food intakes NHANES WWEIA 2013-14 underway.
Dietary supplement group. Calcium dietary supplements national study: The goal of this study is to determine national estimates for calcium and vitamin D content in calcium dietary supplements (DSs) by sampling representative products and measuring their nutrient content. The adult DSs (n=99 in 2-3 lots) were purchased in 6 retail locations nationwide and children’s DSs (n=25, 2 lots) were purchased locally. Calcium and other minerals will be measured by inductively coupled plasma spectrometry, and vitamin D content will be measured using high performance liquid chromatography.
Turmeric dietary supplements: We measured curcumin, demethoxycurcumin (DMC), and bisdemethoxycurcumin (BDMC) content in 2 lots of 54 popular DSs with turmeric as the only or primary ingredient. According to United States Pharmacopeia (USP) identity standards, the ratio of the curcuminoids in turmeric (Curcuma longa) extracts should be 70-80% curcumin, 15-25% DMC and 2.5-6.5% BDMC. For DSs identified as extracts (n=38), 22 had curcumin content >80%. Of biggest concern for adulteration were the DSs with curcumin content above 90% (n=5) or with unusual ratios (n=3) of curcumin/DMC/BDMC. Very high percentages of curcumin could be due to the presence of specific cultivars or turmeric hybrids, or due to adulteration with less expensive synthetic curcumin (which has not been approved by FDA). We also learned that some manufacturers sell the remaining turmeric material after extraction of the majority of curcuminoids. This material, called the “mother extract” has curcuminoid ratios that are similar to two of the DSs in our study. Some study DSs could be a combination of “mother extract” with synthetic curcumin added. The turmeric samples were tested for disintegration using USP specifications, where samples pass if they break apart fully within 30 minutes. The overall sample disintegration pass rate was 87.5%. For 52 DSs, 43 (82.7%) DSs passed in both lots; 4 (7.6%) failed in both lots; 5 (9.6%) DSs had mixed results.
Accomplishments
