Simultaneous analysis of some volatile compounds in food samples by array gas sensors based on polypyrrole nano-composites

Abstract

Purpose The purpose of this paper is to construct an array of sensors using polypyrrole–zinc oxide (PPy–ZnO) and PPy–vanadium (V; chemical formula: V2O5) fibers. To test responses of sensors, a central composite design (CCD) has been used. The results of the CCD technique revealed that the developed sensors are orthogonally sensitive to diacetyl, lactic acid and acetic acid. In total, 20 different mixtures of diacetyl, lactic acid and acetic acid were prepared, and the responses of the array sensors were recorded for each mixture. Design/methodology/approach A response surface regression analysis has been used for correlating the responses of the sensors to diacetyl, lactic acid and acetic acid concentrations during the gas phase in food samples. The developed multivariate model was used for simultaneous determination of diacetyl, lactic acid and acetic acid concentrations. Some food samples with unknown concentrations of diacetyl, lactic acid and acetic acid were provided, and the responses of array sensors to each were recorded. Findings The responses of each sensor were considered as target response in a response optimizer, and by an overall composite desirability, the concentration of each analyte was predicted. The present work suggests the applicability of the response surface regression analysis as a modeling technique for correlating the responses of sensor arrays to concentration profiles of diacetyl, lactic acid and acetic acid in food samples. Originality/value The PPy–ZnO and PPy–V2O5 nanocomposite fibers were synthesized by chemical polymerization. The provided conducting fibers, PPy–ZnO and PPy–V2O5, were used in an array gas sensor system for the analysis of volatile compounds (diacetyl, lactic acid and acetic acid) added to yogurt and milk samples.

Smart films based on bacterial cellulose nanofibers modified by conductive polypyrrole and zinc oxide nanoparticles

“…The newly synthesized BC–PPy, BC–ZnO, and BC–PPy–ZnO films developed in this study had such an excellent capacity for use in food packaging and smart packaging. According to our previous works on gas sensors based on conducting polymers, our results show that in PPy‐based gas sensors, the electrical resistance is changed through exposure to acids, bases, or natural volatile compounds. The use of BC–PPy, BC–ZnO, and BC–PPy–ZnO films in food packaging would make it possible to determine the total volatile compound composition of foods (through food odor), storage time of food, and storage temperature of food.…”

Design and fabrication of starch‐nano clay composite films loaded with methyl orange and bromocresol green for determination of spoilage in milk package

“…Their results confirm our study results. 20 SCMO and SCBG films in the milk bottle with different pH value (3)(4)(5)(6)(7)(8)(9) is obviously detectable. The SCMO film color changes from red color at pH 3 to yellow color in pH 4.5, and the SCBG film color changes from green color at pH 3.8 to blue color in pH 5.5 in milk bottles.…”

“…At pH 6 to 9, the label showed a bold blue color as shown in Figure 1. Table 2 presents Hunter color parameters (L*, a*, b*), YI, Whiteness index, and total color difference (ΔE) of SCMO and SCBG films in milk bottle in different pH (3)(4)(5)(6)(7)(8)(9). According to the color change of According to Figure 6 and considering the data in Table 2 for SCMO film, the parameter a* (green-red) showed a decrease in pH increasing.…”

“…Nano particle composites biodegradable films are a class of nano‐structured materials that are composed of various nanoparticles and biopolymers. These nano composite polymers have superior characters, including mechanical, chemical, physical, and other properties when compared with neat polymers . Nano clays (NC) are nanoparticles that belong to a wider group of clay minerals.…”

“…These nano composite polymers have superior characters, including mechanical, chemical, physical, and other properties when compared with neat polymers. [5][6][7] Nano clays (NC) are nanoparticles that belong to a wider group of clay minerals. They are not new to humankind, and ceramists have been using them in the development of clay products since prehistoric times.…”