Chemical and Biological Sensors for Food-Quality Monitoring and Smart Packaging

Abstract

The growing interest in food quality and safety requires the development of sensitive and reliable methods of analysis as well as technology for freshness preservation and food quality. This review describes the status of chemical and biological sensors for food monitoring and smart packaging. Sensing designs and their analytical features for measuring freshness markers, allergens, pathogens, adulterants and toxicants are discussed with example of applications. Their potential implementation in smart packaging could facilitate food-status monitoring, reduce food waste, extend shelf-life, and improve overall food quality. However, most sensors are still in the development stage and need significant work before implementation in real-world applications. Issues like sensitivity, selectivity, robustness, and safety of the sensing materials due to potential contact or migration in food need to be established. The current development status of these technologies, along with a discussion of the challenges and opportunities for future research, are discussed.

Keywords: food freshness; food quality; sensors; smart packaging.

Figure 1

Representation of the concept of smart and active packaging technology.

Figure 2

(A) Schematic illustrating the release of ethylene during fruit ripening; (B) example of a ripening label by RipeSense^® (RipeSense, Auckland, New Zealand) placed on the top of the package, where color changes from red to yellow according to the ripeness degree. Color development originates from the reaction of evolved gases with the label. Reproduced with permission from Reference [31].

Figure 3

Example of colorimetric freshness sensor for fish via hypoxanthine detection (reproduced with permission from Reference [38]).

Figure 4

Futuristic nanosensor based on wireless network for grain-spoilage detection. (1) Control panel, (2) grain auger, (3) air plenum, (4) fan, (5) auger to transfer grain, if needed, (6) wireless transmitter (reproduced with permission from Reference [1]).

Figure 5

Floating-gate transistor (FGT)-based electronic biosensor structure. (a) Image of FGTs. (b) Circuit for a pair of FGTs. (c) Single FGT schematic showing electrodes, materials, and sample flow. (d) Sensor surface modified with antibodies or aptamers on floating-gate electrode (FG-R), upon binding to gluten, a change in the potential occurs (green line) leading to a shift in voltage value (reprinted with permission from Reference [65]. Copyright 2018, American Chemical Society).

Figure 6

(A) Schematic representation of an ethylene chemoresistive sensor. Mixture of a Cu (I) complex and single-walled carbon nanotubes (SWNTs) were drop-cast between gold electrodes. When ethylene binds to the mixture, resistance changes. (Reproduced with permission from Reference [28]). (B) Dual-channel catalytic-biosensor. Acetaldehyde (AcAl) generated by fruit diffuses through the gas phase to biosensor cells (_AIRCHO-SEAP) genetically engineered to express the Aspergillus nidulans-derived transactivator AlcR that, in the presence of acetaldehyde, activates its cognate promoter PAIR, driving expression of the reporter gene SEAP (AIRCHO-SEAP cells). Ethylene is oxidized to acetaldehyde on PdCl₂ with Cu⁺ based on the Wacker process. The generated acetaldehyde is captured by _AIRCHO-SEAP and converted into SEAP expression, measured as a colorimetric signal (reproduced with permission from Reference [78]).

Figure 7

(A) Volatile organic compounds (VOC) that could accumulate in the presence of fruits and vegetables (reproduced with permission from Reference [79]); (B) VOC freshness indicator in guava packaging (reproduced with permission from Reference [80]).

Figure 8

Allergen-detection chip. (A) Food probes were spotted in addition to positive control and marker (M); (B) detection of corresponding allergens: 1, H₂O; 2, cashews; 3, peanuts; 4, wheat; 5, soybeans; 6, chicken; 7, fish; 8, shrimp; 9, beef (reprinted with permission from Reference [89]. Copyright 2011, American Chemical Society).

Figure 9

LactoSens^® enzymatic biosensor for lactose detection in milk. Reproduced with permission from DirectSens^® (Directsens, Klosterneuburg, Ausria) [100].

Figure 10

Fluorescent DNAzyme probe with specific binding characteristics for E. coli was printed on cyclo-olefin polymer transparent package (reprinted with permission from Reference [112]. Copyright 2018, American Chemical Society).