Search research articles

ABOUT JoVE

Overview Leadership Blog JoVE Help Center

AUTHORS

Publishing Process Editorial Board Scope & Policies Peer Review FAQ Submit

LIBRARIANS

Testimonials Subscriptions Access Resources Library Advisory Board FAQ

RESEARCH

JoVE Journal Methods Collections JoVE Encyclopedia of Experiments Archive

EDUCATION

JoVE Core JoVE Business JoVE Science Education JoVE Lab Manual Faculty Resource Center Faculty Site

Terms & Conditions of Use

Related Concept Videos

Attenuated Total Reflectance (ATR) Infrared Spectroscopy: Overview

Attenuated Total Reflectance (ATR) Infrared Spectroscopy: Overview

Attenuated total reflectance (ATR) infrared spectroscopy is a powerful analytical technique used to study the composition of materials. It is widely employed in chemistry, materials science, forensic science, and other fields where sample characterization is required. ATR has several advantages over traditional transmission IR spectroscopy, including the requirement of little to no sample preparation and the ability to analyze a wide range of samples.
The ATR process begins by directing a beam...

Spectrophotometry: Introduction

Spectrophotometry: Introduction

Spectrophotometry is the quantitative measurement of the absorption, reflection, diffraction, or transmission of electromagnetic radiation through a material as a function of the intensity and wavelength of the radiation. A spectrophotometer is a device used to measure the change in the radiation intensity caused by its interaction with the material.
The essential components of a spectrophotometer include a source of electromagnetic radiation, a slot for placing a material to be analyzed, and a...

UV–Vis Spectroscopy: Woodward–Fieser Rules

UV–Vis Spectroscopy: Woodward–Fieser Rules

UV–Visible absorption spectra of conjugated dienes arise from the lowest energy π&VeryThinSpace;→&VeryThinSpace;π* transitions. The light-absorbing part of the molecule is called the chromophore, and the substituents directly attached to the chromophore are called auxochromes. A strong correlation exists between the absorption maxima, λmax, and the structure of a conjugated π system. The Woodward–Fieser rules predict the value of λmax for a given structure by adding the contributions...

UV–Vis Spectroscopy: Beer–Lambert Law

UV–Vis Spectroscopy: Beer–Lambert Law

The Beer-Lambert law describes the relationship between absorbance and concentration, which combines the principles established by scientists Johann Heinrich Lambert and August Beer. Lambert's law states that when light passes through a medium, the loss in intensity is directly proportional to the original intensity and the path length of the light. Beer's law proposed that the transmittance of a solution remains constant if the product of concentration and path length is constant. The modern...

UV–Vis Spectroscopy of Conjugated Systems

UV–Vis Spectroscopy of Conjugated Systems

Organic compounds with conjugated double bonds show strong absorption features in the UV–visible region of the electromagnetic spectrum attributed to π&VeryThinSpace;→&VeryThinSpace;π* electronic excitations. Generally, a UV–vis absorption spectrum is recorded as a plot of absorbance vs wavelength. The wavelength of maximum absorbance, which manifests as a peak in the absorption spectrum, is denoted as λmax.
One of the factors influencing λmax is the extent of conjugation in the...

IR and UV–Vis Spectroscopy of Aldehydes and Ketones

IR and UV–Vis Spectroscopy of Aldehydes and Ketones

Infrared spectroscopy, also known as vibrational spectroscopy, is mainly used to determine the types of bonds and functional groups in molecules. In aldehydes and ketones, the carbonyl (C=O) bond shows an absorption around 1710 cm-1. The C=O bond vibration of an aldehyde occurs at lower frequencies than that of a ketone. In addition to the C=O absorption in an aldehyde, the aldehydic C–H bond also gives two peaks in the 2700–2800 cm-1 range. This absorption, coupled with the C=O stretching, is...

You might also read

Related Articles

Articles linked to this work by shared authors, journal, and citation graph.

Sort by

Same author

Selective and controllable mechanism of the temperature field in skin tissue under radiofrequency heating: finite element analysis and ex-vivo pig skin experiments.

Journal of thermal biology·2025

Same author

A Two-Step Process for the Synthesis of Densely Functionalized N-Bridged Octahydrobenzofurans and Hexahydrobenzofurans.

Organic letters·2025

Same author

Synthesis and Biological Evaluation of Novel Chlorogenic Acid-Apigenin Conjugates as Anti-acute Gout Agents.

Chemical & pharmaceutical bulletin·2024

Same author

Carvacrol protects mice against LPS-induced sepsis and attenuates inflammatory response in macrophages by modulating the ERK1/2 pathway.

Scientific reports·2023

Same author

A review of the recent advances for the in ovo sexing of chicken embryos using optical sensing techniques.

Poultry science·2023

Same author

Prediction of acrylamide content in potato chips using near-infrared spectroscopy.

Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy·2023

Search research articles

Related Experiment Video

Updated: May 18, 2026

Tea Aroma Analysis Based on Solvent-Assisted Flavor Evaporation Enrichment

Tea Aroma Analysis Based on Solvent-Assisted Flavor Evaporation Enrichment

Published on: May 26, 2023

Characterizing the moisture content of tea with diffuse reflectance spectroscopy using wavelet transform and

Xiaoli Li¹, Chuanqi Xie, Yong He

¹College of Biosystems Engineering and Food Science, Zhejiang University, 866 Yuhangtang Road, Hangzhou 310058, China. xiaolili@zju.edu.cn

Sensors (Basel, Switzerland)

|September 27, 2012

Summary

Diffuse reflectance spectroscopy accurately measures tea's moisture content (MC). Wavelet transform and multivariate analysis reveal a strong correlation between spectral data and MC, enabling precise quantification.

Keywords:

diffuse reflectance spectroscopy moisture content tea wavelength selection wavelet transform

More Related Videos

Characterization of Biological Absorption Spectra Spanning the Visible to the Short-Wave Infrared

Characterization of Biological Absorption Spectra Spanning the Visible to the Short-Wave Infrared

Published on: January 10, 2025

Multimodal Imaging and Spectroscopy Fiber-bundle Microendoscopy Platform for Non-invasive, In Vivo Tissue Analysis

Multimodal Imaging and Spectroscopy Fiber-bundle Microendoscopy Platform for Non-invasive, In Vivo Tissue Analysis

Published on: October 17, 2016

Related Experiment Videos

Last Updated: May 18, 2026

Tea Aroma Analysis Based on Solvent-Assisted Flavor Evaporation Enrichment

Tea Aroma Analysis Based on Solvent-Assisted Flavor Evaporation Enrichment

Published on: May 26, 2023

Characterization of Biological Absorption Spectra Spanning the Visible to the Short-Wave Infrared

Characterization of Biological Absorption Spectra Spanning the Visible to the Short-Wave Infrared

Published on: January 10, 2025

Multimodal Imaging and Spectroscopy Fiber-bundle Microendoscopy Platform for Non-invasive, In Vivo Tissue Analysis

Multimodal Imaging and Spectroscopy Fiber-bundle Microendoscopy Platform for Non-invasive, In Vivo Tissue Analysis

Published on: October 17, 2016

Area of Science:

Agricultural Science
Analytical Chemistry
Spectroscopy

Background:

Accurate determination of moisture content (MC) is crucial for tea quality assessment.
Diffuse reflectance spectroscopy (DRS) offers a non-destructive method for analyzing agricultural products.
Understanding the spectral characteristics related to MC in tea is essential for developing rapid analysis techniques.

Purpose of the Study:

To investigate the effects of moisture content (MC) on the diffuse reflectance spectroscopy of tea.
To develop a quantitative model for determining tea MC using spectral data.
To identify effective wavelengths and feature extraction methods for MC measurement.

Main Methods:

Collected 738 tea samples (fresh, manufactured, partially processed) for spectral measurements (325-1,075 nm).
Applied integrated wavelet transform (WT) and multivariate analysis for quantitative determination.
Utilized WT, principal component analysis (PCA), and kernel principal component analysis (KPCA) for feature extraction.
Employed partial least squares regression, multiple linear regression, and least square support vector machine for calibration.

Main Results:

Wavelet transform (WT) efficiently extracted structural information from spectral data.
A significant correlation (r = 0.991, RMSEP = 0.034) was found between MC and spectral data.
Effective wavelengths for MC measurement were identified in the 888-1,007 nm range using WT.

Conclusions:

Diffuse reflectance spectroscopy, enhanced by wavelet transform and multivariate analysis, is highly effective for measuring tea's moisture content.
The developed spectral analysis method provides a reliable and non-destructive approach for tea quality control.
This study demonstrates the potential of spectroscopic techniques for rapid and accurate assessment of moisture in agricultural commodities.