An e-nose or an e-tongue is a group of gas sensors or chemical sensors that simulate human nose or human tongue. Both e-nose and e-tongue have shown great promise and utility in improving assessments ...of food quality characteristics compared with traditional detection methods.
This review summarizes the application of e-nose and e-tongue in determining the quality-related properties of foods. The working principles, applications, and limitations of the sensors employed by electronic noses and electronic tongues were introduced and compared. Widely employed pattern recognition algorithms, including artificial neural network (ANN), convolutional neural network (CNN), principal component analysis (PCA), partial least square regression (PLS), and support vector machine (SVM), were introduced and compared in this review.
Overall, e-nose or e-tongue combining pattern recognition algorithms are very powerful analytical tools, which are relatively low-cost, rapid, and accurate. E-nose and e-tongue are also suitable for both in-line and off-line measurements, which are very useful in monitoring food processing and detecting the end product quality. The user of e-nose and e-tongue need to strictly control sample preparation, sampling, and data processing.
•The application of e-nose and e-tongue in determining food quality were introduced.•Future trends and limitation of e-nose and e-tongue were discussed.•Working principles of sensors and pattern recognition algorithms were introduced.
Eggs in the United States are typically washed using chemical sanitizers such as quaternary ammonia (QA) or chlorine. Such treatments generate wash water, which could be potentially hazardous to the ...environment. A novel, nonthermal sanitization technique for washing shell eggs using cold plasma-activated water (PAW) was investigated in this study. The inactivation efficacy of PAW on Klebsiella michiganensis and the impact of PAW on the cuticle of the eggshell and shell strength were tested in comparison to QA. Washing inoculated eggs with PAW and QA achieved a similar microbial reduction (>5.28 log CFU/egg). Colorimetric analysis showed that ∆E-value for PAW-treated eggs was significantly lower than QA-treated eggs, suggesting higher cuticle coverage in eggs treated with PAW. The texture analysis to test for shell egg strength indicated that washing eggs with PAW did not affect the structural integrity of the eggshell when compared to eggs washed with QA. According to this study, PAW has the potential as an alternative to commercial sanitizers like QA in the egg-washing industry. PAW does not detrimentally impact shell strength or cuticle coverage and provides similar microbial reduction efficacy.
The determination of the levels of roasting of cocoa relies on expensive analytical equipment, sensory panel, and, in the cases of small processors and growers, empiricism. In this study, cocoa beans ...were roasted for 10–40 min to obtain different levels of roasting, and the images of the beans were captured by a smartphone camera. An extreme learning machine (ELM)-based algorithm was developed to predict the roasting degree of cocoa beans using the images of the cocoa bean cross-sections. A 22-dimension feature vector, including color and texture features, is extracted from each sample, and a total of 350 samples are used to train an ELM network. A majority rule-based voting method was used to make the decision. Experimental results showed that the proposed method achieved a classification accuracy of 93.75%. GC-MS analysis was conducted to determine the chemical compounds in the raw and roasted cocoa beans, and enrichment analysis, principal components analysis, partial least-squares–discriminant analysis, and Pearson correlation analysis were conducted to identify major chemicals respond to roasting time and classify the cocoa beans samples. Caffeine and theobromine were identified as primary chemical compounds that responded to roasting time, and cocoa beans with different levels of roasting were successfully classified.
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•Extreme learning machine (ELM) was used to determine the roasting degree of cocoa beans with high accuracy.•Classifications of cocoa beans were conducted based on images captured by a smartphone camera.•GC-MS analysis has identified the primary chemical compounds that respond to roasting.
Muscadine grape pomace and mixed products with chocolate extracts from three muscadine genotypes exhibiting different berry skin colors (black and bronze) were investigated for total phenolic content ...(TPC), total flavonoid content (TFC), DPPH, FRAP antioxidant activity, and anticancer activity using MDA-MB-468 (MM-468; African American) breast cancer cells. Muscadine berry extracts and mixed products showed cytotoxicity activities of up to 70% against MM-468 breast cancer cells. Cell growth inhibition was higher in ‘macerated Floriana’ with an IC50 value of 20.70 ± 2.43 followed by ‘Alachua’ with an IC50 value of 22.25 ± 2.47. TPC and TFC in macerated MGP powder were (1.4 ± 0.14 and 0.45 ± 0.01 GAE/g FW, respectively), which was significantly higher than those in cocoa powder. Data analysis showed a high association between DPPH, FRAP antioxidant activities, and TPC content and a positive high correlation between anticancer activity and antioxidant capacity and between TPC and anticancer activity. The anticancer and antioxidant effects of muscadine grape pomace and chocolate extracts are attributed to the TPC of extracts, which showed a stronger positive correlation with growth inhibition of African American breast cancer cells. This study would be of great value for food industries as well as other manufacturers who are interested in new food blends.
Plasma-activated microbubble water (PMBW) is an environmentally friendly sanitizer that possesses potent antimicrobial activities and imparts substantial shear stress to food contact surfaces. In ...this study, PMBW, plasma-activated water (PAW), microbubble water (MBW), and chlorine water (100 mg/L) were used to clean PVC tubing inoculated by Klebsiella michiganensis. The sanitizer flow with microbubble was numerically simulated by COMSOL Multiphysics® and the shear stress imparted to the bacteria was calculated. The presence of microbubbles in the flow increased the shear stress imparted to the bacteria. The number of K. michiganensis on the inner surfaces of the pipes was ∼7.4 log CFU/cm2 before washing. PMBW showed the most potent antimicrobial effect, which reduced the number of bacteria by 3.1 log CFU/cm2 at a flow velocity of 1 m/s. PAW, MBW, and chlorine water reduced a similar number of bacteria (2.4 log CFU/ cm2 to 2.6 log CFU/ cm2) at all the selected flow velocities. DI water only reduced the number of K. michiganensis by 0.7 log CFU/ cm2 at 1 m/s flow velocity.
PMBW can potentially be an environmentally friendly sanitizer, which can be employed by food processors to clean their food processing equipment with minimized usage of chemical sanitizers. The technology developed in this study will benefit the food industry by mitigating potential risks of foodborne pathogens without generating environmental hazards.
•Flushing by plasma-activated microbubble water (PMBW) reduced the number of microbes onPVC pipes by ∼4 log CFU/cm2.•PMBW imparted greater stress to K. michiganensis than plasma-activated water did, reducing microbes by 4.1 log CFU/cm2.•The shear stresses of PMBW was ∼ 3 times of non-bubble flow and reduced ∼ 1.5 log CFU/cm2 more K. michiganensis.
Plasma-activated water (PAW) was explored as a clean-in-place agent for inactivating biofilms of Enterobacter aerogenes on the inner surface of a model piping system. Abilities of PAW or chlorine ...solution or distilled water to inactivate the biofilm (~1 × 108 CFU/cm2) attached to the pipe inner surface were compared. Distilled water flowing at 0.11 m/s through the piping system reduced the Enterobacter aerogenes counts on the surface by 0.35, 0.2, and 0.2 log CFU/cm2 on the tees, elbows, and tubing, respectively. However, PAW reduced the E. aerogenes counts on tees, elbows, and tubing by 3.0, 3.2, and 3.8 log CFU/cm2, respectively, which were similar to 100-ppm chlorine water. Increasing the flow velocity to 0.22 m/s made only small difference in terms of biofilm removal. The antimicrobial effect of PAW for Enterobacter aerogenes biofilm on the inner surface of a piping system was comparable to 100-ppm of chlorine solution.
•Plasmas activated water (PAW) was investigated as a clean-in-place sanitizer.•PAW reduced the concentration of E. aerogenes on pipe surface by ~3.5 log CFU/cm2.•Changing the flow regime resulted in ~0.4 log CFU/cm2 of bacterial removal.
Refining and conching are two important processes for chocolate manufacturing, as they help improve the flavor and texture of chocolates. However, methods such as GC-MS for assessing flavor changes ...are expensive. In this study, an e-nose was used to continuously monitor the volatile compounds of cocoa samples undergoing refining, for samples differing in sample mass and degree of roasting. The responses of the e-nose were characterized by three parameters (Rarea, Rpeak and Rwidth) that were able to detect the overall influence of roasting. These values along with sample mass were also used to train Kernel Distribution Models (KDM) which were implemented to better account for temperature and air flow fluctuations. For trained KDMs validated with data taken under the same conditions (sample mass, degree of roasting) the error was ∼1%. When validated under different conditions the error ranged from 2.9 to 9.3%. The degree of roasting had greater affect on the error than the sample mass. A trained KDM can be used to predict the overall volatile compounds at different refining stages, and detect whether the processing variables of sample mass and roasting degree varied from its training samples.
•Cocoa refining/conching is monitored by e-nose.•Kernel distribution model was used to characterizing volatiles profiles.•Corelated cocoa quality to e-nose response.
Hydroponic sweet basil (O. basilicum L.) farming uses a recirculating nutrient solution that may spread waterborne microbial contamination including algae. Plasma, the fourth state of matter, ...generates antimicrobial reactive oxygen and nitrogen species when exposed to water. The objective of this work was to study the effect of plasma-treated water-based nutrient solution on plant growth and in reduction of algae. Basil plants were grown in isolated ebb and flow hydroponic systems (under monitored environmental conditions) using nutrient solution (NS) and plasma-activated nutrient solution (PANS) with two separate treatments: the same irrigation solutions were used in the growth cycle (Treatment 1: NST1 and PANST1 once at the beginning growth cycle) and new irrigation solutions at every week of the growth cycle (Treatment 2: NST2 and PANST2). The plant growth parameters (height, fresh and dry weight, number of branches and nodes, root length, leaf index), quality parameters (color, texture, aroma, and tissue nutrients concentration), and algae concentrations were measured. Compared to NST1, plants grown on PANST1 were significantly taller (up to 12%), had a higher fresh mass (up to 29%) and dry mass (up to 45%), and had a higher greenness value (up to 28%). Algae growth was significantly reduced in the PANST2 reservoir (up to 24%) compared to the NST2 reservoir. It was confirmed that Treatment 1 significantly improved the yield, morphology, and quality of sweet basil plants, while Treatment 2 was best suited to decreasing algae concentration in the hydroponic environment. This preliminary study indicated that PANS could improve the quality and growth of sweet basil in hydroponic farming while controlling the algae growth in the growing environment.
Soft solid foods commonly undergo processing steps such as extrusion, slicing, and shredding. Food tribological behaviors, especially wear behaviors, may be a good indication of their ability to be ...successfully sliced, shredded, or extruded. However, food wear behaviors are currently unknown. Thus, the objective of this study was to characterize the wear behavior of gels with different structures using a numerical model. Wear behaviors of whey protein isolate and κ-carrageenan gels were evaluated under several normal forces. An empirical model for penetration depth was developed that accounted for deformation due to applied force and removal of material. All models had mean absolute error <16 μm indicating good fit. κ-carrageenan gels had the greatest penetration depth among the gels tested; whey protein isolate gels had the lowest. These results were attributed to gel microstructural differences.
•Penetration depth is a combination of compression and wear.•Penetration depth differences were attributed to microstructural differences.•Increased normal force increased both the extent and rate of deformation.•Normal force did not impact extent of wear.
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