Development and evaluation of deep-fried, frozen sweet potato rounds

Objectives of this study were twofold: (a) development of a new form of sweet potato product referred to as sweet potato rounds? and (b) evaluation of samples for quality attributes including sensory, chemical, physical, and caloric content. Sensory panels consisting of 15 university staff and students of food-oriented departments showed some preference for samples prepared in each of the three methods of final preparation: microwave heating, conventional heating and deep-frying. However, samples finished by deep frying were most preferred and samples finished in a microwave oven were least preferred. Proximate composition showed that deep-fried samples had the highest amount of absorbed oil; consequently, these samples contained the highest caloric content when compared to the samples finished in a microwave or conventional oven and deep-fried commercially prepared white potato rounds. Hunter color measurements showed that deep-fried samples were lightest and retained most of their characteristic orange-yellow color. Conventionally-heated and microwave-heated samples were darker and lost some of their natural orange-yellow color. However, small differences existed between samples finished in the two types of ovens. Instron firmness values showed that conventionally-heated samples were firmer than the microwave-heated samples. No comparison was made between samples that were deep-fried or finished by heating in the ovens. However, absolute values showed that deep-fried samples had comparable firmness values as those of conventionally-heated samples. This study shows that acceptable sweet potato rounds can be prepared either by conventional methods using a conventional oven and a deep fryer or by a more convenient but least preferred method using a microwave oven

A rapid method for determination of commercial β-carotene in RBD palm olein by fourier transform infrared spectroscopy.

A rapid method for the determination of commercial β-carotene in refined bleached and deodorized (RBD) palm olein using Fourier transform infrared (FTIR) spectroscopy was developed. The fifty RBD palm olein samples spiked by a known amount of commercial (30%)β-carotene to produce a wide range of concentrations up to 2000 ppm were used. Samples were separated into two groups for the calibration and validation models. The partial least squares (PLS) calibration models for predicting β-carotene was developed by using the FTIR spectral region at 980-915 cm-1 which is associated with trans double bond CH absorption. The accuracy of the method was comparable to that of the HPLC method with a coefficient of determination (R2) and standard error of calibration (SEC) for commercial β-carotene 0.9934 and 52.29, respectively. The FTIR method developed was shown to be efficient, accurate and suitable for routine quality control analysis for the food industry with results obtainable in about 2.5 min

Detection of lard in vegetable oils

The presence of animal fats, in particular lard (pig fat), in any product is of real concern to some communities, especially Muslims and Jews, due to the religious prohibition of these commodities. This is especially so when lard is used as substitute for vegetable oils in foods or other consumer goods such as cosmetics and pharmaceuticals. Manufactures and producers alike should be sensitive towards the issues of unlawful material in these products as halal and kosher markets are expected to proliferate in the coming years. This article highlights some analytical techniques proposed to detect and to quantify lard in vegetable oils such as Fourier transform infrared (FTIR) spectroscopy, differential scanning calorimetry (DSC), chromatographic-based techniques, and electronic nose (EN)

Determination of extra virgin olive oil in quaternary mixture using FTIR spectroscopy and multivariate calibration.

The purpose of this study was to optimize Fourier transform infrared (FTIR) spectroscopy in combination with multivariate calibrations (partial least square and principle component regression) for determination of extra virgin olive oil (EVOO) in quaternary mixture systems with grape seed oil (GSO), rice bran oil (RBO) and walnut oil (WO). FTIR spectra of EVOO in quaternary mixtures were subjected to several treatments including mean centering (MC), standard normal variate, and spectra derivatives. The combined frequency regions of 1200–900 and 2949–2885 cm–1 were used for determination of EVOO. Using partial least square calibration, FTIR normal spectra treated with MC model give the highest values of coefficient of determination (R2) and the lowest values of root mean square error of calibration (RMSEC). The R2 value obtained for the relationship between actual and FTIR predicted value of EVOO was >0.99 with RMSEC value of 1.55% (v/v). The developed PLS model was further used to calculate EVOO in prediction samples, and the root mean square error of prediction obtained was 3.65% (v/v)

Simultaneous quantitative analysis of two functional food oils, extra virgin olive oil and virgin coconut oil using FTIR spectroscopy and multivariate calibration

Two functional food oils, namely extra virgin olive oil (EVOO) and virgin coconut oil (VCO) have been analyzed simultaneously using Fourier transform infrared (FTIR) spectroscopy. The performance of multivariate calibration of principle component regression (PCR) and partial least square regression (PLSR) was evaluated in order to give the best prediction model for such determination. FTIR spectra were treated with several treatments including mean centering (MC), derivatization, and standard normal variate (SNV) at the combined frequency regions of 3050 – 3000, 1660 – 1650, and 1200 – 900 cm-1. Based on its capability to give the highest values of coefficient of correlation (R) for the relationship between actual value of EVOO/VCO and FTIR predicted value together with the lowest values of root mean square error of calibration (RMSEC), PLSR with mean centered-first derivative spectra was chosen for simultaneous determination of EVOO and VCO. It can be concluded that FTIR spectroscopy combined with multivariate calibration of PLSR was successfully applied to simultaneously quantify EVOO and VCO with acceptable parameters

The optimization of FTIR spectroscopy combined with partial least square for analysis of animal fats in quartenary mixtures.

Four types of animal fats, namely lard (LD) and body fats of lamb (LBF), cow (Cow-BF) and chicken (Ch-BF), in quaternary mixtures were quantitatively analyzed using FTIR spectroscopy in combination with multivariate calibration of partial least square (PLS). The animal fats, either individual or in quaternary mixtures, were subjected to horizontal total attenuated total reflectance (HATR) as sample handling technique and scanned at mid-infrared region (4000-650 cm-1) with resolution of 4 cm-1 and with 32 interferograms. PLS calibration revealed that the first derivative FTIR spectrum was well suited for the correlation between actual value of LD and FTIR calculated value. The other animal fats (LBF, Cow-BF and Ch-BF) were better determined using normal FTIR spectra. The coefficient of determination (R 2) obtained using the optimized spectral treatments was higher than 0.99. The root mean standard error of calibration (RMSEC) values obtained were in the range of 0.773-1.55. Analysis of animal fats using FTIR spectroscopy allows rapid, no excessive sample preparation, and can be regarded as "green analytical technique" due to the absence of solvent and chemical reagent used during the analysis

Some Quality Parameters of Intermediate Moisture, Deep-Fried Mackerel (Scomberomorus commersoni, Lacepede)

Intermediate Moisture Deep-fried Mackerel seasoned with local ingredients was prepared by infusion method from an aqueous solution containing PEG 200, sorbic acid and BHA. The products were deep-fried at 190°C for 3 and 4 minutes, resulting in water activity (aw) of 0.84 and 0.80 respectively. Tests on chemical, physical and organoleptic properties were carried out. The Intermediate Moisutre Deepfried Mackerel was found to be generallv acceptable

The chemometrics approach applied to FTIR spectral data for the analysis of rice bran oil in extra virgin olive oil

Among eleven studied vegetable oils, rice bran oil (RBO) has the close similarity to extra virgin olive oil (EVOO) in terms of FTIR spectra, as shown in the score plot of first and second principal components. The peak intensities at 18 frequency regions were used as matrix variables in principal component analysis (PCA). Consequently, the presence of RBO in EVOO is difficult to detect. This study aimed to use the chemometrics approach, namely discriminant analysis (DA) and multivariate calibrations of partial least square and principle component regression to analyze RBO in EVOO. DA was used for the classification of EVOO and EVOO mixed with RBO. Multivariate calibrations were exploited for the quantification of RBO in EVOO. The combined frequency regions of 1200-900 and 3020-3000cm -1 were used for such analysis. The results showed that no misclassification was reported for the classification of EVOO and EVOO mixed with RBO. Partial least square regression either using normal or first derivative FTIR spectra can be successfully used for the quantification of RBO in EVOO. In addition, analysis of fatty acid composition can complement the results obtained from FTIR spectral data

Authentication analysis of cod liver oil from beef fat using fatty acid composition and FTIR spectra

This study aimed to authenticate cod liver oil (CLO) from beef fat (BF) by determining the level of BF as a fat adulterant in CLO. Two instrumental techniques, namely GC-FID for fatty acid analysis and Fourier transform infrared (FTIR) spectroscopy, were exploited for such authentication. The decreased level of some fatty acids, especially eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), could be used as an indicative means to detect the adulteration of CLO with BF. In addition, FTIR spectroscopy combined with partial least-squares (PLS) at frequency regions of 1200-1000 cm -1 was successfully developed for the quantification of BF in CLO. Using the PLS model, the errors obtained in calibration and prediction samples were 0.55% and 0.82% v/v, respectively

FTIR spectroscopy combined with chemometrics for analysis of lard in the mixtures with body fats of lamb, cow, and chicken

Fourier transform infrared (FTIR) spectroscopy combined with chemometrics of partial least square (PLS) and discriminant analysis (DA) has been developed for simple analysis of lard in the mixtures with body fats of lamb (LBF), cow (Cow-BF), and chicken (Ch-BF). The spectral bands correlated with lard, LBF, Cow- BF and Ch-BF as well as their lard blends were scanned, interpreted, and identified. Qualitative differences among FTIR spectra are proposed as a basis for differentiating between the lard and its blends. DA with Mahalanobis distance principle in entire range of mid infrared (3300 – 650 cm-1) was successfully provide an alternate method to differentiate lard and that in the mixtures with LBF, Cow-BF, and Ch-BF. Quantitative analysis using PLS calibration model is proposed to measure the percentages of lard in LBF, Cow-BF, and C-BF at selected fingerprint region (1500 – 900 cm-1). The equation obtained between actual lard concentration in the mixture with LBF and FTIR predicted concentration in calibration model is y = 0.995 x + 0.098 with coefficient of determination (R2) was 0.995 and root mean standard error of calibration (RMSEC) of 0.98. The actual percentages of lard mixed with Cow-BF and Ch-BF were also correlated to FTIR predicted percentages at 1500 – 900 cm-1 using equations of y = 0.999x + 0.016 (R2 = 0.999, RMSEC = 0.61); and y = 1.002x + 0.034 (R2 = 0.998, RMSEC = 0.73), respectively