Development and Application of Dual-Sensors Label in Combination with Active Chitosan-Based Coating Incorporating Yarrow Essential Oil for Freshness Monitoring and Shelf-Life Extension of Chicken Fillet

Abstract

This study aimed for the application of active chitosan coating incorporating yarrow essential oil (YEO) together with the development of an on-package sensor label based on bromocresol purple (BCP) and methyl red (MR) for shelf-life extension and freshness monitoring of chicken breast fillet. Physiochemical and microbiological attributes of chicken meat coated with sole chitosan, YEO, and chitosan + YEO were compared with those of uncoated (control) samples. Chitosan + YEO coated chicken meat stayed fresh with no significant changes (p > 0.05) in pH (5.42−5.56), TVB-N (12.55−15.36 mg N/100 g), TBARs (0.35−0.40 mg MDA/kg) and total aerobic psycrotrophic bacteria (3.97−4.65 log CFU/g) in days 1−15. There was no response of the dual-sensors label toward the variation in chemical and microbiological indicators of chicken meat coated with chitosan + YEO. However, either uncoated, sole chitosan, or sole YEO treatments indicated a three-stage freshness status with the fresh stage belonged to a period earlier than day 7 (with no distinct color change in both sensor labels); the semi-fresh stage corresponded to storage days between 7−9, wherein a gradual color change appeared (MR from pink to orange, BCP from yellow to light purple); and the spoiled stage occurred in day 9 onward with a drastic color change (MR from orange to light yellow, BCP from light purple to deep purple). In general, the dual-sensors successfully responded to the variation of chemical and microbiological indicators and visual color of uncoated samples during storage time. Based on the obtained results, the application of chitosan + YEO coating efficiently prolonged the freshness of chicken breast meat, where on-package dual-sensors systems were able to detect the freshness stages of meat samples during storage time.

Keywords: active coating; chicken meat; freshness sensing; intelligent packaging; shelf life; spoilage.

Figure 1

Color design of freshness dual-sensor labels based on the response of methyl red (MR, outer circle) and bromocresol purple (BCP, inner circle) upon pH variation as an indication of fresh, semi-fresh (should be consumed in hours) and spoiled (should not be consumed) chicken breast fillet.

Figure 2

GC–MS chromatogram of Yarrow (Achillea millefolium L.) essential oil.

Figure 3

Visual inspection of the color of chicken meat samples and their attached sensor labels: effect of different types of coating and chilled storage time.

Figure 4

Effect of pH variation of uncoated chicken meat on dual-sensors label visual color and their mean RGB values.

Figure 5

Effect of different types of chitosan coatings incorporating YEO ((A), control: Ch_0%—YEO_0%, (B): Ch_2%—YEO_0%, (C): Ch_0%—YEO_0.3%, (D): Ch_2%—YEO_0.3%) and chilled storage time on dual-sensors color responses (mean RGB) towards spoiling chicken breast fillets at chilled temperatures. Data are mean of at least triplicate measurements and error bars indicate SDs. MR: methyl red, BCP: Bromocresol purple. (For measurement of the mean RGB of each color sensor, the reader is referred to see Section 2.9 of this article).

Figure 6

Variations of pH (A), TVB-N (B), and TBARs (C) values in relation to dual-sensors color responses (measured as mean RGB) in chicken meat samples without coating (control, (A1–C1) and coated with chitosan incorporating YEO (Ch_2%—YEO_0.3%, (A2–C2)) during chilled storage days. Data are mean of at least triplicate measurements and error bars indicate SDs. MR: methyl red, BCP: Bromocresol purple. Onset of detection and threshold of spoilage in relation to pH, TVB-N, and TBARs values has been shown by black arrows.

Figure 7

Variations of total aerobic psycrotrophic bacteria (APB) count (A), chroma index (C*) (B) and whiteness index (WI) (C) in relation to dual-sensors color responses (measured as mean RGB) in chicken meat samples without coating (control, (A1–C1)) and coated with chitosan containing YEO (Ch_2%—YEO_0.3%, (A2–C2)) during chilled storage days. Data are mean of at least triplicate measurements and error bars indicate SDs. MR: methyl red, BCP: Bromocresol purple. Onset of detection and threshold of spoilage in relation to APB, C*, and WI values has been shown by arrows.