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Öğe Application of a Portable Infrared Instrument for Simultaneous Analysis of Sugars, Asparagine and Glutamine Levels in Raw Potato Tubers(Springer, 2015) Ayvaz, Huseyin; Santos, Alejandra M.; Moyseenko, Jennifer; Kleinhenz, Matthew; Rodriguez-Saona, Luis E.The level of reducing sugars and asparagine in raw potatoes is critical for potato breeders and the food industry for production of commonly consumed food products including potato chips and French fries. Our objective was to evaluate the use of a portable infrared instrument for the rapid quantitation of major sugars and amino acids in raw potato tubers using single-bounce attenuated total reflectance (ATR) and dial path accessories as an alternative to time-consuming chromatographic techniques. Samples representing a total of 84 experimental and commercial potato varieties harvested in two consecutive growing seasons (2012 and 2013) were used in this study. Samples had wide ranges of sugars determined by HPLC-RID (non-detectable (ND)-7.7 mg glucose, ND-9.4 mg fructose and 0.4-5.4 mg sucrose per 1 g fresh weight), and asparagine and glutamine levels determined by GC-FID (0.7-2.9 mg and 0.3-1.7 mg per 1 g fresh weight). Infrared spectra collected from 64 varieties were used to create partial least squares regression (PLSR) calibration models that predicted the sugar and amino acid levels in an independent set of 16 validation potato varieties. Excellent linear correlations between infrared predicted and reference values were obtained. PLSR models had a high correlation coefficient of prediction (rPred > 0.95) and residual predictive deviation (RPD) values ranging between 3.1 and 5.5. Overall, the results indicated that the models could be used to simultaneously predict sugars, free asparagine and glutamine levels in the raw tubers, significantly benefiting potato breeding, certain aspects of crop management, crop production and research.Öğe Improving the screening of potato breeding lines for specific nutritional traits using portable mid-infrared spectroscopy and multivariate analysis(Elsevier Sci Ltd, 2016) Ayvaz, Huseyin; Bozdogan, Adnan; Giusti, M. Monica; Mortas, Mustafa; Gomez, Rene; Rodriguez-Saona, Luis E.Efficient selection of potato varieties with enhanced nutritional quality requires simple, accurate and cost effective assays to obtain tuber chemical composition information. In this study, 75 Andean native potato samples from 7 Solanum species with different colors were characterized and quantified for their anthocyanin, phenolics and sugar content using traditional reference methods. IR (infrared) spectra of potato extracts were collected using a portable infrared system and partial least squares regression (PLSR) calibration models were developed. These models were validated using both full cross-validation and an independent sample set giving strong linear correlation coefficients of prediction (rPred) > 0.91 and standard error of prediction (SEP) of 24 mg/100 g phenolics, 7 mg/100 g monomeric anthocyanins, 0.1 g/100 g reducing sugars and 0.12 g/100 g sucrose. Overall, portable infrared system with PLSR showed great potential to facilitate potato breeding and certain aspects of crop management, material selection for potato processing and related research by providing alternative prediction models. (C) 2016 Elsevier Ltd. All rights reserved.Öğe Kinetic modeling of ascorbic acid degradation of pineapple juice subjected to combined pressure-thermal treatment(Elsevier Sci Ltd, 2018) Dhakal, Santosh; Balasubramaniam, V. M.; Ayvaz, Huseyin; Rodriguez-Saona, Luis E.A study was conducted to investigate and model kinetic degradation of ascorbic acid in freshly prepared pineapple juice subjected to various pressure (0.1, 300,450 and 600 MPa)-thermal (30, 75, 85 and 95 degrees C) treatment combinations. Experiments were conducted using a semi-custom made high pressure kinetic tester as well as an aluminum thermal kinetic tester. Thermal degradation of ascorbic acid was described with simple first order kinetics. The thermal rate constants (k (75 _95 degrees c, 0.1 MPa)) and activation energy (E-a) for ascorbic acid degradation reaction varied in the range of 0.004-0.006 per min and 14.22-29.78 kJ/mol, respectively. Within the experimental conditions of the study (300-600 MPa at 30 degrees C for holding times up to 15 min) high pressure processing did not alter ascorbic acid content (535.5-564.5 mg/kg). Combined pressure-thermal treatment (300-600 MPa at 75-95 degrees C) degraded ascorbic acid with increasing thermal intensity and was modeled using first order fractional conversion kinetics model. The lower asymptote value ([A](infinity)/[A](0))rate constants (k(75 _95 degrees c, 0.1 MPa)) and Ea were in the range of 77-85%, 0.108 to 0.138 per min and 17.4-43.8 kJ/mol, respectively. Similarly, pressure sensitivity (Delta V-not equal) was similar to 0 and -2.99 cm(3)/mol at 30 and 95 degrees C, respectively. Knowledge gained from the study can be useful for food processors to optimize high pressure treatment conditions for pineapple juice products. (C) 2017 Elsevier Ltd. All rights reserved.Öğe Monitoring multicomponent quality traits in tomato juice using portable mid-infrared (MIR) spectroscopy and multivariate analysis(Elsevier Sci Ltd, 2016) Ayvaz, Huseyin; Sierra-Cadavid, Andrea; Aykas, Didem P.; Mulqueeney, Brett; Sullivan, Scott; Rodriguez-Saona, Luis E.In this study, a novel portable infrared spectrometer was evaluated for rapid and simultaneous determination of glucose, fructose, total reducing sugars, soluble solids (degrees Brix), serum viscosity, Bostwick consistency, predicted paste Bostwick value and pH. A total of 350 hot-break juices from two consecutive years (2013 and 2014) including 66 different varieties grown in 6 counties of California, USA, were used in this study. Duplicate spectra for each tomato juice were collected using the transmission accessory of the portable infrared spectrometer at 50 gm fixed path length. Samples were randomly divided into calibration (n = 280) and external validation (n = 70) sets and partial least squares (PLS) regression was used to develop calibration models to predict all the variables (quality traits) in the validation samples based on the tomato juice spectral data (r(pred) > 0.82). Overall, our validated chemometric models allowed rapidly (-2 min) predicting all the quality traits in tomato juice samples with no sample preparation. (C) 2016 Elsevier Ltd. All rights reserved.Öğe Portable Infrared Spectrometer to Characterize and Differentiate Between Organic and Conventional Bovine Butter(Springer, 2015) Pujolras, Marcal Plans; Ayvaz, Huseyin; Shotts, Mei-Ling; Pittman, Richard A., Jr.; Herringshaw, Sarah; Rodriguez-Saona, Luis E.The performance of a portable infrared system combined with pattern recognition to discriminate between organically and conventionally produced bovine butter samples as well as to predict the levels of conjugated linoleic acid (CLA) were evaluated. Sixty butter (27 organic and 33 conventional) samples were used in this study. Bovine butter-fat were applied onto an attenuated total reflectance infrared (ATR-IR) accessory equipped with a five-bounce ZnSe crystal set at 65 A degrees C for spectral collection. In addition, ATR-IR spectra of bovine butter were directly collected at room temperature to avoid phase separation. The fatty acid profile and the levels of CLA were determined using reference FAME-GC-FID analysis. SIMCA models showed well separated clusters that discriminated between organic and conventional bovine butters due to C=C trans bending out of the plane vibration modes band at 967 cm(-1). Additionally, strong PLSR models were developed to predict CLA levels using butter-fat and bovine butter spectra with SEP of 0.05 % and RPD of 4.7, indicating that the models are suitable for quality control applications. Portable IR technology offers the ability for in situ analysis of butters that is much less time consuming than current analytical practices for authentication and quality control efforts by the industry.Öğe Raman Spectroscopy for Food Quality: Assessment Uncovering Adulteration and Ensuring Authenticity(CRC Press, 2024) Ayvaz, Huseyin; Yao, Siyu; Morta, Mustafa; Temizkan, Riza; Akpolat, Hacer; Rodriguez-Saona, Luis E.The globalization of the food market, the prevalence of economically motivated adulteration, and the scarcity of high-value food sources have posed significant challenges to ensuring food authenticity in the industry. The assessment of food authenticity has now become a matter of utmost importance, necessitating the adoption of rapid and robust methods. While well-established techniques are available for analysis, many are not always feasible because of the need for high-priced instrumentation and proficient operators, excessive time requirements, and the destructive nature of the methods. However, Raman spectroscopy has been positioned as an attractive technology offering high-speed and nondestructive fingerprinting capabilities to monitor sample characteristics of foods. Improvements in optical technology and portable instruments have allowed field-deployable devices and have made it practical to detect adulteration from production to the market. An extensive literature has demonstrated the convenience and efficacy of these instruments in fulfilling the needs of the food industry. This chapter highlights the recent advancements in research studies focusing on the utilization of Raman spectroscopy for the rapid determination of food adulteration and authentication. These developments showcase the potential of Raman spectroscopy as a valuable tool in addressing the challenges posed by food fraud. The ongoing progress in Raman spectroscopy and its applications in food authenticity assessment represents a significant step forward in combating adulteration and ensuring the integrity of our food supply. Further research and technological advancements in this field will enhance the capabilities of Raman spectroscopy, providing the industry with increasingly reliable, efficient, and practical methods to combat food adulteration and authenticate the foods we consume. © 2025 selection and editorial matter, Ugur Tamer, Mustafa Culha, and smail Hakki Boyaci; individual chapters, the contributors.Öğe The use of infrared spectrometers to predict quality parameters of cornmeal (corn grits) and differentiate between organic and conventional practices(Academic Press Ltd- Elsevier Science Ltd, 2015) Ayvaz, Huseyin; Plans, Marcal; Towers, Brittany N.; Auer, Angela; Rodriguez-Saona, Luis E.Benchtop and handheld NIR and portable mid-infrared (MIR) spectrometers were evaluated as rapid methods for differentiating between organic and conventional cornmeal and to measure quality parameters of cornmeal used for production of snack foods. Twenty-seven conventional and eleven organic cornmeal samples were obtained from a local manufacturer of grain-based products. Reference quality parameters measured included moisture content, ash content, pasting properties and particle size. Soft independent modeling of class analogy (SIMCA) analysis accurately classified between organic and conventional cornmeal samples (interclass distance > 3.7) based on differences in the C=O signal associated with side chain vibrations of acidic amino acids. Residual predictive deviation (RPD) values for partial least squares regression (PLSR) models developed, ranged between 2.3 and 9.6. Overall, our data supports the capability of infrared systems to classify between organic and conventional cornmeal, and to predict important quality attributes of cornmeal for the snack food industry. (C) 2015 Elsevier Ltd. All rights reserved.Öğe Understanding Tomato Peelability(Wiley, 2016) Ayvaz, Huseyin; Santos, Alejandra M.; Rodriguez-Saona, Luis E.Approximately 75% of all tomatoes in the United States are consumed as processed and 25% as fresh. One of the first steps during processing involves removal of the peel and, unfortunately, more than 25% of the fruits (as measured by total weight) can be lost due to overpeeling. Additionally, conventional peeling applications have a negative environmental impact. Given the great potential economic benefits, many scientists have conducted research to attempt optimizing or predicting peeling performance when processing tomatoes. The literature regarding tomato peelability is contradictory in many cases; and several topics have been subject to ample debate over the years. Divergent conclusions are probably not due to faulty investigations, but rather to the extreme variability found among tomato cultivars, the effect of growing seasons, and maybe even the effect of climatic conditions on the day of harvest or during transportation to the processing plants. This review provides an in-depth background needed for a better understanding of tomato physiology, maturation, and composition, as these could possibly influence the ease of peeling or peelability. The research studies directly involved with peeling tomatoes and predicting peelability are discussed in this paper as well. Different peeling methods, peeling grading scales, and fruit tagging procedures are presented, as well as experiments evaluating the effect that fruit defects, maturity, growing conditions, and other factors can have on the ease of peeling. Novel approaches for peelability prediction by means of spectroscopic and magnetic resonance technology are also discussed in this review.Öğe Vibrational Spectroscopy in Food Traceability(Elsevier, 2020) Ayvaz, Huseyin; Akpolat, Hacer; Sezer, Banu; Boyaci, Ismail Hakki; Rodriguez-Saona, Luis E.[No abstract available]
