Sensory quality evaluation for appearance of needle-shaped green tea based on computer vision and nonlinear tools.

Tea is one of the three greatest beverages in the world. In China, green tea has the largest consumption, and needle-shaped green tea, such as Maofeng tea and Sparrow Tongue tea, accounts for more than 40% of green tea (Zhu et al., 2017).

Detection of meat-borne trimethylamine based on nanoporous colorimetric sensor arrays.

Trimethylamine (TMA) is a key measurement indicator for meat spoilage. In order to develop simple, cheap, and sensitive sensors for TMA detection, a nanoporous colorimetric sensor array (NCSA) was developed. A sol-gel method has been used to obtain TiO2 nanoporous film as substrate material to improve the sensitivity and stability of the CSA.

A new room temperature gas sensor based on pigment-sensitized TiO2 thin film for amines determination.

A new room temperature gas sensor was fabricated with pigment-sensitized TiO2 thin film as the sensing layer. Four natural pigments were extracted from spinach (Spinacia oleracea), red radish (Raphanus sativus L), winter jasmine (Jasminum nudiflorum), and black rice (Oryza sativa L. indica) by ethanol.

Determination of pork spoilage by colorimetric gas sensor array based on natural pigments.

A new colorimetric gas-sensor array based on four natural pigments, that were extracted from spinach (Spinacia oleracea), red radish (Raphanus sativus L.), winter jasmine (Jasminum nudiflorum), and black rice (Oryza sativa L. indica), was developed for pork freshness evaluation.

A new sensor for ammonia based on cyanidin-sensitized titanium dioxide film operating at room temperature.

Design and fabrication of an ammonia sensor operating at room temperature based on pigment-sensitized TiO2 films was described. TiO2 was prepared by sol-gel method and deposited on glass slides containing gold electrodes. Then, the film immersed in a 2.

Rapid detecting total acid content and classifying different types of vinegar based on near infrared spectroscopy and least-squares support vector machine.

More than 3.2 million litres of vinegar is consumed every day in China. There are many types of vinegar in China.

Determination of total flavonoids content in fresh Ginkgo biloba leaf with different colors using near infrared spectroscopy.

Total flavonoids content is often considered an important quality index of Ginkgo biloba leaf. The feasibility of using near infrared (NIR) spectra at the wavelength range of 10,000-4000cm(-1) for rapid and nondestructive determination of total flavonoids content in G. biloba leaf was investigated.

Study on classification of soy sauce by electronic tongue technique combined with artificial neural network.

Electronic tongue as an analytical tool coupled with pattern recognition was attempted to classify 4 different brands and 2 categories (produced by different processes) of Chinese soy sauce. An electronic tongue system was used for data acquisition of the samples. Some effective variables were extracted from electronic tongue data by principal component analysis (PCA).

[Rapid diagnostics of early phosphorus deficiency in mini-cucumber plants under protected cultivation by near infrared spectroscopy].

The morphological symptom of phosphorus deficiency at early stage is similar to the appearance of leaf aging process in preliminary phase, so that visual diagnostics of phosphorus deficiency in mini-cucumber plants at early stage is practically impossible. Near infrared reflectance spectra contain information about differences in compositions of leaf tissues between phosphorus-deficient plants and healthy plants. In the present paper, near infrared reflectance spectroscopy was used to provide diagnostic information on phosphorus deficiency of mini-cucumber plants grown under non-soil conditions.

[Determination of taste quality of green tea using FT-NIR spectroscopy and variable selection methods].

The present paper was attempted to study the feasibility to determine the taste quality of green tea using FT-NIR spectroscopy combined with variable selection methods. Chemistry evaluation, as the reference measurement, was used to measure the total taste scores of green tea infusion. First, synergy interval PLS (siPLS) was implemented to select efficient spectral regions from SNV preprocessed spectra; then, optimal variables were selected using genetic algorithm (GA) from these selected spectral regions by siPLS, and the optimal model was achieved with Rp = 0.

[Measurement of chlorophyll content and distribution in tea plant's leaf using hyperspectral imaging technique].

Chlorophyll content and distribution in plant's leaves is an important index in estimation of plant nutrition information. In the present work, chlorophyll content and distribution in tea plant's leaves were measured by hyperspectral imaging technique. First, hyperspectral image data were captured from tea plant's leaves; then seven kinds of algorithms were used to extract the characteristic parameters from hyperspectral image; finally, seven fitted models were developed using the characteristics vectors and the reference measurements of chlorophyll contents respectively.

[A new method of characteristic wavelength sub-range selection of near infrared spectroscopy].

To improve and simplify the prediction model of carotenoid content of cucumber leaves, genetic algorithm (GA) combined with Metropolis acceptance criterion of simulated annealing algorithm (SAA) as well as interval partial least square (iPLS) were proposed and used to establish the calibration models of carotenoid content against cucumber leaves spectra. The cucumber leaves spectra data were divided into 40 intervals, among which 7 subsets, i. e.

[Identification of egg freshness using near infrared spectroscopy and one class support vector machine algorithm].

Near infrared (NIR) spectroscopy combined with pattern recognition was attempted to discriminate the freshness of eggs. The algorithm of one-class support vector machine (OC-SVM) was employed to solve the classification problem due to imbalanced number of training samples. In this work, 86 samples of eggs (71 samples of fresh eggs and 15 samples of unfresh eggs) were surveyed by Fourier transform NIR spectroscopy.

[Study of simplification of prediction model for kiwifruit firmness using near infrared spectroscopy].

To simplify the prediction model of kiwifruit firmness, SNV was used to preprocess the near infrared (NIR) spectra (1 000-2 500 nm)of kiwifruit. PLS model simplification by optimizing spectral intervals and decreasing the number of factors through net analyte preprocessing (NAP)was carried out. Results showed that the performance of NAP/PLS model is the best.

[Study on the identification of tea using near infrared reflectance spectroscopy].

A rapid tea identification method by near infrared spectroscopy coupled with pattern recognition based on principal components analysis and Mahalanobis' distance technique was proposed. Four famous brand teas in China were studied, including Longjing tea, Biluochun tea, Maofeng tea and Tieguanyin tea in the experiment. In the spectral region between 6 500 and 5 300 cm(-1), through preprocessing method of MSC (multiplicative scatter comection), the prediction model was built.

[The determination of beef tenderness using near-infrared spectroscopy].

The prediction of beef tenderness was studied using near-infrared spectroscopy. The absorption spectra of beef samples were collected between 4,000 and 10,000 cm(-1), the maximum shear force of these samples was obtained using the Warner-Bratzler attachment, and subjective judgment for the tenderness grade of beef was studied. Beef samples with the maximum shear force less than 6 kg were regarded as tender, and their tenderness grade was defined as the value of 1.