applied sciences  
A Miniaturized and Low-Cost Near-Infrared Spectroscopy Measurement System for Alfalfa Quality Control  
[PERSON] 1  
1 Department of Physical and Analytical Chemistry, University of Oviedo, 33006 Oviedo, Spain;  
melendrerascanada@univioires (C.M. ); [EMAIL_ADDRESS] (J.M.C.-F)  
2 Department of Electrical, Electronics, Computers and Systems Engineering, University of Oviedo, 33204 Gijon, Spain; [EMAIL_ADDRESS] (Correspondence: [EMAIL_ADDRESS] (A.S.); [EMAIL_ADDRESS] (F.F. ); Tel. : +34-985-103-583 (A.S.); +34-985-182-552 (F.F)  
[PERSON], [PERSON], [PERSON], [PERSON], [PERSON], F. A Miniaturized and Low-Cost Near-Infrared Spectroscopy Measurement System for Alfalfa Quality Control. _Appl. Sci._**2023**, 13, 9290. [[https://doi.org/10.3309/appl3169290](https://doi.org/10.3309/appl3169290)]([https://doi.org/10.3309/appl3169290](https://doi.org/10.3309/appl3169290))  
[PERSON], [PERSON], [PERSON], [PERSON], [PERSON], F. A Miniaturized and Low-Cost Near-Infrared Spectroscopy Measurement System for Alfalfa Quality Control. _Appl. Sci._**2023**, 13, 9290. [[https://doi.org/10](https://doi.org/10)]([https://doi.org/10](https://doi.org/10)). in the production line. In this review [7], [PERSON] et al. introduce scientific and technical reports using the NIRS to evaluate food, agriculture, and forest products. In addition to the advantages of this technique, the possibility of developing miniaturized NIR systems that are easy to use, and specialized in the quality control of the raw forages used in animal feed, makes it possible to increase quality control (sampling). Thus, [PERSON] et al. [8] evaluate several hand-held NIR instruments for the precision and accuracy of the currently available calibrations for dry-matter and forage nutritive value. [PERSON] [9] outlines the technologies used in portable spectroscopy, and [PERSON] et al. [10] discuss the characteristics of miniaturized NIR sensors in comparison to benchtop laboratory spectrometers. The use of easy-to-use portable NIRS instrumentation minimizes time losses, because nonspecialized personnel are able to analyse samples on site, and a real-time response is achieved as soon as the analysis is carried out. These characteristics are some of those required in precision farming [11]. Several miniaturized spectrophotometers have been developed and marketed in the last decade, some of which are extremely small, light, and inexpensive. By allowing measurements in the field, at the point of delivery, production, sale, purchase, and use, these spectrometers transform NIRS technology. Table 1 lists some commercial miniaturized NIRSs, and presents their main characteristics, as found on the websites of the manufacturers. This work evaluates the feasibility of a miniaturized and low-cost NIRS measurement system for alfalfa quality control. The core of this system is a NIR spectrometer based on the Texas Instruments NIRscan Nano evaluation module (EVM). It has a large sensing area and high resolution to analyse forage samples. To evaluate the feasibility of the prototype, different ways of presenting the sample, intact (raw) or ground, were studied. This equipment has already been tested for use in liquid sample analysis [12], with a specific cuvette for liquid samples. For this purpose, alfalfa samples were analysed. Alfalfa is one of the main forages used to feed animals, due to its high biomass production, and protein and fiber contents. In summary, this work contributes:  
* to confirming the efficiency of the proposed NIRS measurement system;
* to identifying the qualities of the equipment; and
* to looking for aspects to improve and implement in the future.