Recent Applications of Potentiometric Electronic Tongue and Electronic Nose in Sensory Evaluation

Physicochemical and chemosensory properties of pomegranate (Punica granatum L.) seeds under various oven-roasting conditions

This study investigated the effects of oven-roasting temperature (160, 180, and 200 ℃) and time (5, 10, 15, and 20 min) on pomegranate seeds. Physicochemical properties, such as color (L*, a*, and b* values), browning index (BI), total phenolic and flavonoid contents, 2,2-diphenyl-1-picrylhydrazyl radical scavenging capacity, and chemosensory properties, including taste and volatile compounds, were analyzed. The L* and a* values, and level of sourness, umami, sweetness, and terpenes decreased, whereas the b* value, BI, and level of saltiness, bitterness, furan derivatives, pyrazines, and sulfur-containing compounds, increased with roasting time. The findings of this study showed that the positive roasting conditions for pomegranate seeds were 10-20 min at 160 ℃ and, 5-10 min at 180 ℃. This study is expected to be used as a primary reference for selecting the optimal oven-roasting conditions in which positive effects appear and for developing products utilizing pomegranate seeds.

Determination of heavy metals in edible oils by a novel voltammetry taste sensor array

Herein, a novel voltammetry taste sensor array (VTSA) using pencil graphite electrode, screen-printed electrode, and glassy carbon electrode was used to identify heavy metals (HM) including Cad, Pb, Sn and Ni in soybean and rapeseed oils. HMs were added to edible oils at three concentrations of 0.05, 0.1 and 0.25 ppm, and then, the output of the device was classified using a chemometric classification method. According to the principal component analysis results, PG electrode explains 96% and 81% of the variance between the data in rapeseed and soybean edible oils, respectively. Additionally, the SP electrode explains 91% of the variance between the data in rapeseed and soybean oils. Moreover, the GC electrode explains 100% and 99% of the variance between the data in rapeseed and soybean edible oils, respectively. K-nearest neighbor exhibited high capability in classifying HMs in edible oils. In addition, partial least squares in the combine of VTSA shows a predict 99% in rapeseed oil. The best electrode for soybean edible oil was GC.

Novel animal product substitutes: A new category of plant-based alternatives to meat, seafood, egg, and dairy products

Many consumers are adopting plant-centric diets to address the adverse effects of livestock production on the environment, health, and animal welfare. Processed plant-based foods, including animal product analogs (such as meat, seafood, egg, or dairy analogs) and traditional animal product substitutes (such as tofu, seitan, or tempeh), may not be desirable to a broad spectrum of consumers. This article introduces a new category of plant-based foods specifically designed to overcome the limitations of current animal product analogs and substitutes: novel animal product substitutes (NAPS). NAPS are designed to contain high levels of nutrients to be encouraged (such as proteins, omega-3 fatty acids, dietary fibers, vitamins, and minerals) and low levels of nutrients to be discouraged (such as salt, sugar, and saturated fat). Moreover, they may be designed to have a wide range of appearances, textures, mouthfeels, and flavors. For instance, they could be red, orange, green, yellow, blue, or beige; they could be spheres, ovals, cubes, or pyramids; they could be hard/soft or brittle/pliable; and they could be lemon, thyme, curry, or chili flavored. Consequently, there is great flexibility in creating NAPS that could be eaten in situations where animal products are normally consumed, for example, with pasta, rice, potatoes, bread, soups, or salads. This article reviews the science behind the formulation of NAPS, highlights factors impacting their appearance, texture, flavor, and nutritional profile, and discusses methods that can be used to formulate, produce, and characterize them. Finally, it stresses the need for further studies on this new category of foods, especially on their sensory and consumer aspects.

Check-all-that-apply (CATA)- and rate-all-that-apply (RATA)-based sensometric assessment of germinated-wheat beverages

Sensometrics assesses sensory perspectives in consumer research using statistics and various methodologies. This study evaluated consumer responses to hot and cold germinated-wheat beverages in check-all-that-apply (CATA) and rate-all-that-apply (RATA) assessments using sensometric statistical approaches, including Cochran's Q test, penalty-lift analysis, and multiple factor analysis. Hot beverages (HB) were prepared by infusion using different amounts of germinated wheat (HB_1: 0.8 g/100 mL, HB_2: 2 g/100 mL, and HB_3: 4 g/100 mL), while cold beverages (CB) were made using cooled boiled germinated wheat with varying concentrations (CB_1: 25 g/L, CB_2: 50 g/L, and CB_3: 75 g/L). Results of the CATA study suggested that consumers preferred HB_1 and CB_1 because they expressed the sensory characteristics associated with liking, including "barley tea flavor", "neat taste", and "nutty taste", while "bitterish taste", "stuffy taste", and "astringent taste" were undesirable attributes. "Browning index", "barley tea odor", and "nutty taste" showed significant differences (p < 0.05) in both favorable and unfavorable rating scores. Overall, CB_1 elicited a clear taste and odor with fewer negative emotions. These findings demonstrate the usefulness of the sensometric approach combined with CATA and RATA analyses to obtain more easily interpretable results on the sensory perception of consumers to new food products.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13197-023-05884-z.

Aerobic spore-forming bacteria associated with ropy bread: Identification, characterization and spoilage potential assessment

Aerobic spore-forming (ASF) bacteria have been reported to cause ropiness in bread. Sticky and stringy degradation, discoloration, and an odor reminiscent of rotting fruit are typical characteristics of ropy bread spoilage. In addition to economic losses, ropy bread spoilage may lead to health risks, as virulent strains of ASF bacteria are not uncommon. However, the lack of systematic approaches to quantify physicochemical spoilage characteristics makes it extremely difficult to assess rope formation in bread. To address this problem, the aim of this study was to identify, characterize and objectively assess the spoilage potential of ASF bacteria associated with ropy bread. Hence, a set of 82 ASF bacteria, including isolates from raw materials and bakery environments as well as strains from international culture collections, were identified by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS) and their species identity confirmed by 16S rRNA and gyrA or panC gene sequencing. A standardized approach supported by objective colorimetric measurements was developed to assess the rope-inducing potential (RIP) of a strain by inoculating autoclaved bread slices with bacterial spores. In addition, the presence of potential virulence factors such as swarming motility or hemolysis was investigated. This study adds B. velezensis, B. inaquosorum and B. spizizenii to the species potentially implicated of causing ropy bread spoilage. Most importantly, this study introduces a standardized classification protocol for assessing the RIP of a bacterial strain. Colorimetric measurements are used to objectively quantify the degree of breadcrumb discoloration. Furthermore, our results indicate that strains capable of inducing rope spoilage in bread often exhibit swarming motility and virulence factors such as hemolysis, raising important food quality considerations.

Improving the flavor of tilapia fish head soup by adding lipid oxidation products and cysteine

Deodorization and umami enhancement are important challenges in promoting and consuming fish products. The aim of this study was to establish whether exogenous addition of oxidized lipids and cysteine can improve the fishy, umami and create a characteristic flavor in tilapia fish head soup. The results revealed that adding oxidized lipids and cysteine enhanced the sensory attributes of fish head soup and promoted the production of pleasant-tasting amino acids and fewer bitter amino acids in the Maillard reaction. Additionally, the combination increased the levels of well-flavored aldehydes, esters, heterocyclic compounds and less hydrocarbons in the fish head soup. Among the 13 volatile compounds screened, nine were identified as characteristic aromas of fish head soup, including nonanal, (E,E)-2,4-decadienal, 1-octen-3-ol, (E)-2-decenal, acetic acid, hexanal, heptanal, 2-octenal, and decanal. Exogenous lipid oxidation products, fatty acid oxidation, and Maillard reaction can improve the aroma and umami of tilapia fish head soup.

High-performance bioelectronic tongue for the simultaneous analysis of phenols, sugars and organic acids in wines

BACKGROUND

Electronic tongues have been widely used to analyze wines. However, owing to the complexity of the matrix, the problem is not completely solved and further improvements are required.

RESULTS

A high-performance potentiometric bioelectronic tongue (bio-ET) specifically devoted to the assessment of wine components is presented. The novelty of this system is due to two innovative approaches. First, the improved performance is obtained through the use of potentiometric biosensors based on carboxylated polyvinyl chloride (PVC) membranes, where enzymes (glucose oxidase, tyrosinase, laccase, and lyase) specific to compounds of interest are linked covalently. Second, the performance is further enhanced by introducing electron mediators (gold nanoparticles or copper phthalocyanine) into the PVC membrane to facilitate the electron transfer process. Individual sensors exposed to target analytes (glucose, catechol, cysteine, or tartaric acid) show a linear behavior, with limits of detection in the region of 10-4  mol L-1 for all the compounds analyzed, with excellent reproducibility (coefficient of variation lower than 3%). Sensors combined to form a bio-ET show excellent capabilities. Principal component (PC) analysis can discriminate monovarietal white wines (PC1 77%; PC2 15%) and red wines (PC1 63%; PC2 30%). Using partial least squares, the bio-ET can provide information about chemical parameters, including glucose, total polyphenols, total anthocyanins, free and total sulfur dioxide, total acidity, and pH with R2 between 0.91 and 0.98 in calibration and between 0.89 and 0.98 in validation.

CONCLUSIONS

This advanced instrument is able to assess the levels of seven parameters in a single measurement, providing an advantageous method to the wine industry. © 2023 Society of Chemical Industry.

Review of Applications of Cyclodextrins as Taste-Masking Excipients for Pharmaceutical Purposes

It is widely recognized that many active pharmaceutical ingredients (APIs) have a disagreeable taste that affects patient acceptability, particularly in children. Consequently, developing dosage forms with a masked taste has attracted a lot of interest. The application of cyclodextrins as pharmaceutical excipients is highly appreciated and well established, including their roles as drug delivery systems, solubilizers and absorption promoters, agents that improve drug stability, or even APIs. The first work describing the application of the taste-masking properties of CDs as pharmaceutical excipients was published in 2001. Since then, numerous studies have shown that these cyclic oligosaccharides can be effectively used for such purposes. Therefore, the aim of this review is to provide insight into studies in this area. To achieve this aim, a systematic evaluation was conducted, which resulted in the selection of 67 works representing both successful and unsuccessful works describing the application of CDs as taste-masking excipients. Particular attention has been given to the methods of evaluation of the taste-masking properties and the factors affecting the outcomes, such as the choice of the proper cyclodextrin or guest-host molar ratio. The conclusions of this review reveal that the application of CDs is not straightforward; nevertheless, this solution can be an effective, safe, and inexpensive method of taste masking for pharmaceutical purposes.

Neuroimaging Approach: Effects of Hot and Cold Germinated Wheat Beverages on Electroencephalographic (EEG) Activity of the Human Brain

Neuroimaging studies using electroencephalography (EEG) have been crucial in uncovering brain activity in sensory perception, emotion regulation, and decision-making. Despite tea's global popularity, its temperature-related neural basis remains underexplored. This study investigated the effect of hot and cold germinated wheat beverages (HB and CB) in changes of brain waves using EEG. Four distinct approaches and topographical assessments were performed to gain deeper insights into the impact of EEG signals in the human brain. The four approaches showed different impacts of HB and CB intake, as all EEG spectral powers increased after drinking HB and decreased after consumption of CB. Significant increases in delta and theta waves were observed as a result of drinking HB, but significant decreases in alpha and beta waves were observed after drinking CB. The topographic maps illustrate the significant effects of HB more prominently than those of CB, displaying greater changes in delta, theta, and beta. These findings suggest the intake of HB is probably related to relaxation, calmness, mindfulness and concentration, while the intake of CB is related to alertness, attention, and working memory. Ultimately, the neuroscientific approaches provided in this study could advance consumer-based research on beverage consumption.

A Guide to Best Practice in Sensory Analysis of Pharmaceutical Formulations

It is well established that treatment regime compliance is linked to the acceptability of a pharmaceutical formulation, and hence also to therapeutic outcomes. To that end, acceptability must be assessed during the development of all pharmaceutical products and especially for those intended for paediatric patients. Although acceptability is a multifaceted concept, poor sensory characteristics often contribute to poor patient acceptability. In particular, poor taste is often cited as a major reason for many patients, especially children, to refuse to take their medicine. It is thus important to understand and, as far as possible, optimise the sensory characteristics and, in particular, the taste/flavour/mouthfeel of the formulation throughout the development of the product. Sensory analysis has been widely practiced, providing objective data concerning the sensory aspects of food and cosmetic products. In this paper, we present proposals concerning how the well-established principles of sensory analysis can best be applied to pharmaceutical product development, allowing objective, scientifically valid, sensory data to be obtained safely. We briefly discuss methodologies that may be helpful in reducing the number of samples that may need to be assessed by human volunteers. However, it is only possible to be sure whether or not the sensory characteristics of a pharmaceutical product are non-aversive to potential users by undertaking sensory assessments in human volunteers. Testing is also required during formulation assessment and to ensure that the sensory characteristics remain acceptable throughout the product shelf life. We provide a risk assessment procedure to aid developers to define where studies are low risk, the results of a survey of European regulators on their views concerning such studies, and detailed guidance concerning the types of sensory studies that can be undertaken at each phase of product development, along with guidance about the practicalities of performing such sensory studies. We hope that this guidance will also lead to the development of internationally agreed standards between industry and regulators concerning how these aspects should be measured and assessed throughout the development process and when writing and evaluating regulatory submissions. Finally, we hope that the guidance herein will help formulators as they seek to develop better medicines for all patients and, in particular, paediatric patients.

Evaluation of the Chemosensoric Properties of Commercially Available Dog Foods Using Electronic Sensors and GC-MS/O Analysis

Pet owners think of their animals as part of their family, which further promotes the growth of the pet food market, encouraging pet owners to select nutritious, palatable, and high-quality foods for pets. Therefore, the evaluation of taste and volatile compounds in pet foods is essential to improve palatability. In this study, the sensory characteristics of taste and odor compounds in 10 commercially available dry dog foods were investigated using electronic tongue (E-tongue), electronic nose (E-nose), gas chromatography-mass spectrometry (GC-MS), and gas chromatography-olfactometry (GC-O). Dry dog foods were separated based on the sensory properties of taste and volatile compounds through the multivariate analysis of integrated results of the E-tongue and E-nose. A total of 67 odor active compounds were detected through GC-MS and GC-O, and octanal, nonanal, 2-pentyl furan, heptanal, and benzaldehyde were identified as key odor compounds which may have positive effects on food intake. The multivariate analysis was used to classify samples based on key odor compounds. Volatile compounds responsible for aroma properties of samples were evaluated using GC-O and multivariate analysis in this present study for the first time. These results are expected to provide fundamental data for sensory evaluation in producing new dog foods with improved palatability.

Juice Quality Evaluation with Multisensor Systems-A Review

E-nose and e-tongue are advanced technologies that allow for the fast and precise analysis of smells and flavours using special sensors. Both technologies are widely used, especially in the food industry, where they are implemented, e.g., for identifying ingredients and product quality, detecting contamination, and assessing their stability and shelf life. Therefore, the aim of this article is to provide a comprehensive review of the application of e-nose and e-tongue in various industries, focusing in particular on the use of these technologies in the fruit and vegetable juice industry. For this purpose, an analysis of research carried out worldwide over the last five years, concerning the possibility of using the considered multisensory systems to test the quality and taste and aroma profiles of juices is included. In addition, the review contains a brief characterization of these innovative devices through information such as their origin, mode of operation, types, advantages and disadvantages, challenges and perspectives, as well as the possibility of their applications in other industries besides the juice industry.