Measurement of Volatile Fatty Acids in Silage through Odors with Nanomechanical Sensors

Abstract

The measurement of volatile fatty acids (VFAs) is of great importance in the fields of food and agriculture. There are various methods to measure VFAs, but most methods require specific equipment, making on-site measurements difficult. In this work, we demonstrate the measurements of VFAs in a model sample, silage, through its vapor using an array of nanomechanical sensors—Membrane-type Surface stress Sensors (MSS). Focusing on relatively slow desorption behaviors of VFAs predicted with the sorption kinetics of nanomechanical sensing and the dissociation nature of VFAs, the VFAs can be efficiently measured by using features extracted from the decay curves of the sensing response, resulting in sufficient discrimination of the silage samples. Since the present sensing system does not require expensive, bulky setup and pre-treatment of samples, it has a great potential for practical applications including on-site measurements.

Sorption Kinetic Parameters from Nanomechanical Sensing for Discrimination of 2-Nonenal from Saturated Aldehydes

“…This is because sensing signal of nanomechanical sensors in static mode operation is obtained from sorption-induced expansion, , which is governed by sorption kinetics as long as the absorbed molecules including water do not exceed the capacity of receptor materials. It should be noted that the signal responses of PMMA to aldehydes fluctuated significantly under the humidified conditions because PMMA has hydrophilic nature and is sensitive to water . This led to poor fitting results.…”

Effects of fermentative quality of corn silage on lactation, blood metabolites, and rumen fermentation in dairy cows

“…For simplified monitoring the degree of aerobic deterioration, so far, changes in temperature or pH have been used as indicators (Shan et al, 2021). We recently demonstrated that one of the nanomechanical sensors MSS for detecting VFAs in silage and showed the sufficient discrimination of the silage samples (Minami et al, 2023). This sensor has clearly discriminated the quality of corn silage used in this study, and feeding trial was conducted for practical use of devise.…”

“…The preparation of corn silage has been shown in a previous report (Minami et al, 2023). Briefly, whole plant corn (Zea mays L.) was mown at the yellow ripe stage and ensiled in an underground silo for six months.…”

“…Several attempts have been made to estimate the fermentation quality of silage. Recently, we demonstrated that the volatile fatty acids (VFAs) in silage can be estimated from its vapor using an array of nanomechanical sensors -Membrane-type Surface stress Sensors (MSS) (Minami et al, 2023). In addition, this type of sensor array combined with machine learning can be used to quantify specific target components, such as alcohol in liquors (Shiba et al, 2017(Shiba et al, , 2018.…”

“…For the practical use of such a device with a certain accuracy, it is necessary to obtain many data of different silages with feeding trials and to clarify the relationship between silage quality as determined by the sensor and dairy cow performance. Therefore, we used the two corn silages judged by a developed sensor to be of different qualities (Minami et al, 2023) and studied the feeding effects on dairy performance. Namely, we fed partial mixed rations (PMRs) that contain these corn silages to lactating cows and examined the relationship between fermentation quality and feed intake, lactation performance, plasma metabolites, rumen fermentation, and CH 4 emissions of dairy cows.…”