Lirong Xu

Novel method for the producing area identification of Zhongning Goji berries by electronic nose

High-quality Zhongning Goji berries (ZNG) are illegally adulterated in the market by adding non-ZNG (NZNG). An accurate, rapid, and effective approach for the producing area identification of ZNG is needed to protect the geographical indications of Goji berry products and to ensure fair trade. Samples from different regions were collected and their odors were detected by an electronic nose (E-nose). Principal component analysis (PCA), cluster analysis (CA), and linear discriminant analysis (LDA) were employed to build identification models. The E-nose models were further verified by gas chromatography-mass spectrometry (GC-MS). The identification rates of the PCA, CA, and LDA models were 91.0%, 98.9%, and 100%, respectively. The PCA and CA models presented good results, and the LDA model showed optimum performance. These conditions indicate the feasibility of using the E-nose technique for ZNG identification. GC-MS analysis revealed differences and similarities in total ion current chromatograms between ZNG and NZNG.

A novel approach to discriminate Lycium barbarum from the Zhongning area using FT-IR spectroscopy and chemometrics

An increasing number of fake and inferior Lycium barbarum fruits from the Zhongning production area have appeared in the market due to large demands of consumers. The present study focused on the classification and identification of Zhongning Lycium barbarum (ZNL) from different production areas using Fourier transform infrared (FT-IR) spectroscopy coupled with chemometrics. Results revealed that the spectral region between 1909–1311 cm−1 was found to be useful for both classification and identification of ZNL. FT-IR combined with discriminant analysis (DA) and soft independent modeling of class analogy were used for classification and identification of ZNL among different Lycium production areas in China. Also, FT-IR coupled with DA can successfully classify and identify ZNL from the other production areas. Recognition rates of the calibration and validation sets were 94.0% and 100%, respectively. Thus, the proposed method is a useful tool to identify ZNL among different Lycium production areas in China.

Efficient Salt-aided Aqueous Extraction of Bitter Almond Oil

BACKGROUND Salt-aided aqueous extraction (SAAE) is an inexpensive and environmentally friendly method of oil extraction that is influenced by many factors. In the present study, we investigated the effect of SAAE on bitter almond oil yield. RESULTS This study used sodium bicarbonate solution as extraction solvent and the optimal extraction parameters predicted by Box-Behnken design (i.e., concentration of sodium bicarbonate, 0.4 mol L-1 ; solvent-to-sample ratio, 5:1; extraction temperature, 84 °C; extraction time, 60 min), for oil recovery of 90.9%. The physiochemical characteristics of the extracted oil suggest that the quality was similar to that of the aqueous enzymatic extracted oil. Moreover, the content of hydrocyanic acid (HCN) in bitter almond oil was found to be less than 5 mg kg-1 , which was lower compared to that obtained by other reported methods. Results of microanalysis indicated that SAAE led to significant improvement in oil yield by allowing the release of oil and decreasing the emulsion fraction. Therefore, extraction of bitter almond oil by SAAE is feasible. CONCLUSION These results demonstrate that extraction of bitter almond oil by SAAE based on the salt effect is feasible on a laboratory scale.

A rapid method for evaluating the edible oil oxidative stability during ambient storage by FTIR spectroscopy using a mesh cell

A rapid method for evaluating the edible oil oxidative stability during ambient storage was established by Fourier transform infrared (FTIR) procedures, using a mesh cell as the spectral acquisition accessory. The prepared oil samples were exposed to visible light at ambient temperature (23 ± 2 °C), and the oxidative stability of edible oils was predicted by comparing the time when the peroxide value (PV) reached 20 and 100 meq. kg−1 by using the mesh cell-based oxidation method (MCOM) and bulk oxidation. The results indicated that the MCOM is 2.6 to 4.2 times faster than the oxidized oils in bulk when the PV reached 20 and 100 meq. kg−1, respectively. The oxidation changes in some functional groups can be monitored in real time during ambient storage using the mesh cell-based FTIR technique. Compared with traditional oxidation methods, the use of the mesh cell-based FTIR technique provides a simple, practical, and rapid means for evaluating the oxidative stability of edible oils during ambient storage.

Application of Fourier Transform Infrared Spectroscopy for the Quality and Safety Analysis of Fats and Oils: A Review

Abstract Fats and oils are essential food components. Their quality and safety pose major concerns for consumers and food producers because of factors such as oxidation and rancidity, excessive levels of trans fatty acid (TFA), and widespread adulteration. Thus, a rapid and easy-to-use technique must be exploited for quality parameter evaluation and monitoring to ensure the edibility, safety, and quality of fats and oils. In the last decades, Fourier transform infrared (FTIR) spectroscopy has shown great potential in analyzing fats and oils given its speed and simplicity. FTIR-based analytical techniques for common intrinsic quality parameters, including peroxide value, free fatty acid, moisture, TFA, iodine value, as well as oxidation stability, adulteration, and classification of various fats and oils, are summarized in this review. The advantages and disadvantages of selected infrared spectral accessories and sample preparation and spectral processing methods are highlighted. The prospects and reformative aspects for future application of the FTIR technique in the field of fats and oils are also discussed. This review may serve as a basis for applying FTIR not only in future research but also in the fat and oil industries.

Novel method based on fourier transform infrared spectroscopy for determining fat acidity of cereal products

ABSTRACT A novel method based on Fourier transform infrared spectroscopy was developed to determine fat acidity (FA) in cereal products. Disposable double polyethylene films were used as a spectral acquisition accessory. Oil was extracted from cereal products using a solvent followed by ultrasonication. The calibration curve of peak height (1716/1600 cm−1) and FA was developed by using hexanoic acid added to rapeseed oil and solvent solution. The oil-dependent absorption of the calibration at a peak of 1716/1600 cm−1 was corrected by the first overtone of ester at 3479/3518 cm−1. Subsequently, different types of blind samples were used to validate the calibration. An excellent linear relationship was determined between the FA determined using the proposed method and the ISO 7305:1998 method, with a correlation coefficient of 0.9980. Therefore, the proposed procedure can be used as an alternative to the standard method in determining the FA of cereal products.