Mukti Singh

Site-specific study of corn protein, oil, and extractable starch variability using nit spectroscopy

To determine variability in corn protein, oil, starch, and extractable starch, near-infrared transmission (NIT) was used on samples from 640 sub plots that were planted with two varieties at four population levels, five nitrogen levels, and two nitrogen application methods. A GLM analyses of variance indicated NIT protein content increased significantly with increases in nitrogen rate and changes in method of nitrogen application. Protein ranged from 5.7% to 11.0% over all plots and treatments. The highest protein content occurred on plots receiving 202 kg N/ha; while the lowest occurred on plots receiving no nitrogen. Oil percentages did not vary significantly with nitrogen rate and they ranged from 2.2% to 4.3%. Starch content and extractable starch decreased significantly as nitrogen rate increased. Extractable starch ranged from 63.4% to 72.1%. The highest extractable starch level of 72.1% occurred on the plots with no nitrogen application; while the lowest extractable starch occurred on plots receiving 202 kg N/ha. Starch content ranged from 72.0% to 76.1%. Soil Plant Analysis Development (SPAD) readings increased significantly with nitrogen rate, application method, and population increases. They ranged from a mean of 44.5 at the lowest nitrogen level to 52.2 at the highest nitrogen level. Yield increased from a mean of 10.5 tonnes/ha at the 0 nitrogen level to 11.5 tonnes/ha at the 202 kg N/ha level. Extractable starch had a negative correlation (R2 = -0.76) with protein and a positive correlation (R2 = 0.65) with starch content.

Maize Starch Yield Calibrations with Near Infrared Reflectance

Abstract Maize starch yield is affected by variety, environmental growing conditions, and drying conditions. One-hundred gram starch yield tests that predict actual wet milling starch yield were used as a reference method for developing an extractable starch calibration on a NIRSystems Model 6500 spectrophotometer. A maize starch yield calibration was developed from 940 samples and used to predict a validation set of 304 samples. It had a standard error of prediction (SEP) of 1·06, a coefficient of determination r2 of 0·77 and a ratio of performance to deviations (rpd) of 2·1. This indicates about 95% of similar samples could have starch yield predicted by near-infrared reflectance within about±2·1%. The calibration should be successful in segregating maize lots for high and low starch yield percentages.

Preparation of Margarines from Organogels of Sunflower Wax and Vegetable Oils

UNLABELLED It was previously reported that sunflower wax (SW) had high potential as an organogelator for soybean oil-based margarine and spread products. In this study, 12 other vegetable oils were evaluated in a margarine formulation to test feasibility of utilization of SW as an alternative to solid fats in margarine and spread products containing these oils. The minimum quantity of SW required to form a gel with these oils ranged from 0.3% to 1.0% (wt.). Organogels were prepared from the vegetable oils with 3%, 5% and 7% SW and were tested for firmness as well as melting behaviors using differential scanning calorimetry. These organogels were also incorporated into a margarine formulation. All of the vegetable oil organogels produced relatively firm margarines. The margarines prepared from organogels containing 3% (wt.) SW had greater firmness than commercial spreads, whereas margarines made from 7% SW were softer than commercial stick margarines. However, dropping points of the margarine samples were higher than those of commercial spread and margarine products. Margarine firmness was modestly inversely correlated with the amount of polar compounds in the oils and did not correlate with fatty acid compositions. This study demonstrates the feasibility of using a number of healthy vegetable oils rich in polyunsaturated fatty acids to make healthy margarine and spread products by utilizing SW as an organogelator. PRACTICAL APPLICATION This study showed that sunflower wax could be used as an alternative to traditional solid fats for the development of new margarine and spread products from a variety of healthy vegetable oils.

Yogurt fermentation in the presence of starch-lipid composite.

The fermentation of yogurt in the presence of 0.5%, 1.0%, 1.5%, and 2.0% starch-lipid composite (SLC) was investigated. The pH, viscosity, and morphology of the mix were monitored during the fermentation process. The rate of drop in pH with time during incubation was not affected by the addition of SLC. However, it was found that the presence of SLC caused faster aggregation, which was clearly evidenced by the viscosity variation during the process of fermentation. An examination of the morphologies confirmed that aggregation occurred earlier in the presence of SLC and SLC did not form phase-separated domains. This study concludes that SLC would serve as a good additive (fat replacer and stabilizer) for the production of yogurt.

Effect of Purified Oat β‐Glucan on Fermentation of Set‐Style Yogurt Mix*

UNLABELLED Effect of oat β-glucan on the fermentation of set-style yogurt was investigated by incorporating 0%, 0.1%, 0.2%, 0.3%, 0.4%, and 0.5% of purified oat β-glucan into the yogurt mix. It was found that levels up to 0.3% resulted in yogurts with quality characteristics similar to the control yogurt. Higher levels of β-glucan however retarded the fermentation process with noticeable difference in the characteristics of the yogurt. Examination of the morphologies of yogurt with and without β-glucan revealed that β-glucan formed aggregates with casein micelle and did not form phase-separated domains. This research demonstrated that β-glucan could be added to yogurt up to 0.3%, which meets the nutrient guidelines, to have added nutritional benefits. PRACTICAL APPLICATION Yogurt is known for its beneficial effects on human health and nutrition. Yogurt production and consumption is increasing in the United States every year. However, it is lacking in β-glucans, which are recognized for their nutritional importance as functional bioactive ingredients. The main objective was to develop and characterize low-fat yogurts with added β-glucan. This research demonstrated that β-glucan could be added to yogurt up to 0.3%, which meets the nutrient guidelines for added nutritional benefits, without affecting the characteristics of yogurt significantly. This study will benefit the dairy industry by generating new products offering healthy alternatives.

Detection of Corn Adulteration in Brazilian Coffee (Coffea arabica) by Tocopherol Profiling and Near-Infrared (NIR) Spectroscopy

Coffee is a high-value commodity that is a target for adulteration, leading to loss of quality and causing significant loss to consumers. Therefore, there is significant interest in developing methods for detecting coffee adulteration and improving the sensitivity and accuracy of these methods. Corn and other lower value crops are potential adulterants, along with sticks and coffee husks. Fourteen pure Brazilian roasted, ground coffee bean samples were adulterated with 1-20% of roasted, ground corn and were analyzed for their tocopherol content and profile by HPLC. They were also analyzed by near-infrared (NIR) spectroscopy. Both proposed methods of detection of corn adulteration displayed a sensitivity of around 5%, thus representing simple and fast analytical methods for detecting adulteration at likely levels of contamination. Further studies should be conducted to verify the results with a much larger sample size and additional types of adulterants.

Navy Bean Flour Particle Size and Protein Content Affect Cake Baking and Batter Quality1

Whole navy bean flour and its fine and coarse particle size fractions were used to completely replace wheat flour in cakes. Replacement of wheat flour with whole bean flour significantly increased the protein content. The protein content was adjusted to 3 levels with navy bean starch. The effect of navy bean flour and its fractions at 3 levels of protein on cake batter rheology and cake quality was studied and compared with wheat flour samples. Batters prepared from navy bean flour and its fractions had higher viscosity than the cake flour. Reducing the protein content by addition of starch significantly lowered the viscosity of cake batters. The whole navy bean flour and coarse bean fraction cakes were softer than cakes made with wheat flour but had reduced springiness. Principal component analysis showed a clear discrimination of cakes according to protein. It also showed that low protein navy bean flour cakes were similar to wheat flour cakes. Navy bean flour with protein content adjusted to the level of cake (wheat) flour has potential as a healthy alternative in gluten-free cakes.

Site-Specific Study of Corn Protein, Oil, and Extractable Starch Variability using NIT Spectroscopy

Global positioning systems enable precise pinpointing of field locations for fertilizer and herbicide applications as well as moisture and yield monitoring. To determine variability in corn protein, oil, starch, and extractable starch, near-infrared transmission (NIT) was used on samples from 640 sub plots that varied in nitrogen, population and hybrid. Protein increased while starch content and extractable starch decreased significantly with increases in nitrogen. Oil percentages did not vary significantly with nitrogen fertility increases.

Amylose–Potassium Oleate Inclusion Complex in Plain Set‐Style Yogurt

Health and wellness aspirations of U.S. consumers continue to drive the demand for lower fat from inherently beneficial foods such as yogurt. Removing fat from yogurt negatively affects the gel strength, texture, syneresis, and storage of yogurt. Amylose-potassium oleate inclusion complexes (AIC) were used to replace skim milk solids to improve the quality of nonfat yogurt. The effect of AIC on fermentation of yogurt mix and strength of yogurt gel was studied and compared to full-fat samples. Texture, storage modulus, and syneresis of yogurt were observed over 4 weeks of storage at 4 °C. Yogurt mixes having the skim milk solids partially replaced by AIC fermented at a similar rate as yogurt samples with no milk solids replaced and full-fat milk. Initial viscosity was higher for yogurt mixes with AIC. The presence of 3% AIC strengthened the yogurt gel as indicated by texture and rheology measurements. Yogurt samples with 3% AIC maintained the gel strength during storage and resulted in low syneresis after storage for 4 wk.

Corn Moisture Meter Comparisons to the Air Oven in Illinois

The objective of this study was to compare moisture meter readings to the 103°C 72-hr air oven reference method for naturally wet corn during the Fall of 2002. Each sample was tested by the Illinois Department of Agriculture in triplicate in 12 moisture meters and in the air oven. Moisture meters tested included: the Dickey-john GAC 2100, GAC 2000, and GAC II; Motomco 919, 919E, and 919ES; Steinlite SL 95, SB 900, SS 250, RC, RCT; and Burrows 700. Compared to the oven, most of the meters performed within the acceptable limits up to approximately 25% moisture content on combine and hand-shelled corn. Above 25% moisture and with hand-shelled corn, many of the moisture meters tended to read lower than the air oven. The low readings were believed to be caused by hand-shelled samples of corn. Based on only one crop year with predominately handshelled samples no recommendations for changes in moisture meter calibrations were made.