Meat and Fish Freshness Assessment by a Portable and Simplified Electronic Nose System (Mastersense).

The evaluation of meat and fish quality is crucial to ensure that products are safe and meet the consumers' expectation. The present work aims at developing a new low-cost, portable, and simplified electronic nose system, named Mastersense, to assess meat and fish freshness. Four metal oxide semiconductor sensors were selected by principal component analysis and were inserted in an "ad hoc" designed measuring chamber. The Mastersense system was used to test beef and poultry slices, and plaice and salmon fillets during their shelf life at 4 °C, from the day of packaging and beyond the expiration date. The same samples were tested for Total Viable Count, and the microbial results were used to define freshness classes to develop classification models by the K-Nearest Neighbours' algorithm and Partial Least Square-Discriminant Analysis. All the obtained models gave global sensitivity and specificity with prediction higher than 83.3% and 84.0%, respectively. Moreover, a McNemar's test was performed to compare the prediction ability of the two classification algorithms, which resulted in comparable values (p > 0.05). Thus, the Mastersense prototype implemented with the K-Nearest Neighbours' model is considered the most convenient strategy to assess meat and fish freshness.

Enriching gluten-free rice pasta with soybean and sweet potato flours.

The development of innovative rice products is a way to exploiting and adding value to low-grade African rice varieties. To this purpose, rice-based pasta was enriched with flours from soybean and orange-fleshed sweet potato, that are common ingredients in the African tradition. Four different formulations based on pre-gelatinized rice flour and liquid egg albumen, and containing soybean and/or sweet potato (up to 20%) were prepared and characterized via a multidisciplinary approach. Soybean and sweet potato enrichment leads to a decrease in the pasta consistency and in significant changes in the color of the resulting samples, likely due to Maillard-type reactions. E-sensing approaches indicated that the sensory profile of the various pasta products strongly depends on the type of enrichment. Data collected after cooking suggest that both soybean and sweet potato have a role in defining the firmness and water absorption, as well as the optimum cooking time. Structural characterization of proteins in the uncooked products indicates the presence of protein aggregates stabilized by hydrophobic interactions and disulfide bonds in all samples, although structural properties of the aggregates related to specific compositional traits.

Development of a Hydroxypropyl-ß-Cyclodextrin-Based Liquid Formulation for the Oral Administration of Propranolol in Pediatric Therapy.

Propranolol (PPN) is widely used in children to treat various cardiovascular diseases. The availability of a suitable PPN solution should avoid recourse to extemporaneous preparations of unknown/limited stability, as commonly made in hospital pharmacies. However, the development of pediatric PPN solutions is hindered by their instability to light and stability at pH ≈ 3, bitter taste, and the need to improve palatability and avoid co-solvents, flavoring agents, or preservatives that are potentially toxic. In this study, cyclodextrin (CD) complexation has been exploited to develop a safe, stable, and palatable oral pediatric solution of PPN. An initial screening among various CDs allowed us to select HPßCD for its good complexing ability and no toxicity. Drug-HPßCD physical mixtures or co-ground systems (1:1 or 1:2 mol:mol) were used to prepare 0.2% w/v drug solutions. Photo stability studies evidenced the protective effect of HPßCD, revealing a reduction of up to 75% in the drug degradation rate after 1 h of exposure to UV radiation. Storage stability studies showed unchanged physical-chemical properties and almost constant drug concentration after 6 months and under accelerated conditions (40 °C), despite the less aggressive pH (≈5.5) of the solution. The electronic tongue test proved that the HPßCD taste-masking properties improved the formulation palatability, with a 30% reduction in drug bitterness.

Reformulating Couscous with Sprouted Buckwheat: Physico-Chemical Properties and Sensory Characteristics Assessed by E-Senses.

In the frame of reformulating food products for valorizing underutilized crops and enhancing both the nutritional and sensory characteristics of traditional foods, this study explored the potential impact of sprouting on some features of couscous prepared from buckwheat. Specifically, the impact of two sprouting times (48 h and 72 h) and two enrichment levels (25% and 50%) on physical properties (bulk density, hydration properties), cooking behavior (e.g., texture), chemical features (e.g., total phenolic content, rutin and quercetin), antioxidant activity (DPPH assay), and sensory traits (by means of electronic nose, tongue, and eye) was considered. Results showed that the replacement of 50% of pre-gelatinized buckwheat flour with 72 h-sprouted buckwheat flour resulted in a couscous with a higher content of phenolic compounds (including rutin and quercetin) and antioxidant activity; the related values further increased upon cooking. Moreover, except for the hardness and gumminess that were worsened (i.e., their values increased), cohesiveness and resilience improved in the presence of sprouted buckwheat (i.e., their values increased). Finally, the overall sensory traits improved with the addition of 50% sprouted buckwheat, since both bitterness and astringency decreased in the reformulated couscous.

Valorization of Common (Fagopyrum esculentum Moench.) and Tartary (Fagopyrum tataricum Gaertn.) Buckwheat in Gluten-Free Polenta Samples: Chemical-Physical and Sensory Characterization.

In recent years, increasing attention has been addressed to buckwheat, an interesting minor crop with an excellent nutritional profile that contributes to the sustainability and biodiversity of the agri-food system. However, the high content of rutin and quercitin present in this pseudocereal can elicit undesirable sensory properties, such as bitterness and astringency, that can limit its exploitation in food formulations. The aim of the present study was to characterize six gluten-free porridge-type formulations (called polenta) prepared using corn and buckwheat flour. Specifically, polenta samples were prepared adding common (CB) or Tartary buckwheat (TB) flour at 20% (CB20; TB20), 30% (CB30; TB30), and 40% (CB40; TB40) to corn flour. Product characterization included sensory and instrumental analyses (electronic tongue, colorimeter, and Texture Analyzer). Products containing Tartary buckwheat were darker, firmer, and characterized by a higher intensity of bitter taste and astringency than those prepared with common buckwheat. In this context, the impact of buckwheat species seems to be more important at 30% and 40% levels, suggesting that lower additions may mask the differences between the species. The gathered information could support the food industry in re-formulating products with buckwheat. Finally, findings about the relationship between instrumental and sensory data might be exploited by the food industry to decide/choose what indices to use to characterize new formulations and/or new products.

Influence of Two Innovative Packaging Materials on Quality Parameters and Aromatic Fingerprint of Extra-Virgin Olive Oils.

The performance of two innovative packaging materials was investigated on two Sardinian extra-virgin olive oils (Nera di Gonnos and Bosana). In particular, a transparent plastic film loaded with a UV-blocker (packaging B) and a metallized material (packaging C) were compared each other and to brown-amber glass (packaging A). During accelerated shelf-life tests at 40 and 60 °C, the evolution of quality parameters (i.e., acidity, peroxide value, K270, and phenolic content) was monitored, together with the aromatic fingerprint evaluated by electronic nose. Packaging B resulted in the best-performing material in protecting oil from oxidation, due to its lower oxygen transmission rate (0.1 ± 0.02 cm3/m2 24 h) compared to packaging C (0.23 ± 0.04 cm3/m2 24 h). At the end of storage, phenolic reduction was on average 25% for packaging B and 58% for packaging C, and the aromatic fingerprint was better preserved in packaging B. In addition, other factors such as the sanitary status of the olives at harvesting and the storage temperature were demonstrated to have a significant role in the shelf life of packaged extra-virgin olive oil.

Influence of Cooking Conditions on Nutritional Properties and Sensory Characteristics Interpreted by E-Senses: Case-Study on Selected Vegetables.

This study investigates the effects of three cooking methods (boiling, steaming and microwaving) on the nutritional and physical properties of cauliflowers, carrots and sweet potatoes; e-senses were applied to interpret the sensory characteristics according to physico-chemical aspects. The nutritional quality was evaluated by determining the concentrations of key components and the antioxidant activity; e-sense data, combined with texture parameters, were processed by a principal component analysis. The cooking method and time significantly influenced the quality of the three products. Boiling, which detrimentally affected ascorbic acid, total phenolic concentration and antioxidant activity, enhanced carotene accessibility. Steaming produced losses in ascorbic acid, increasing total phenolics and carotenoids. Microwaving resulted in minor changes in ascorbic acid concentrations, preserved carotenoids and increased total phenolics. The nutritional quality was better preserved or enhanced using shorter cooking times. The elaboration of the data collected by the e-senses showed a clear evolution according to the cooking method and time. The results helped to determine the cooking method that best preserves the nutritional properties of the vegetables, highlighting the applicability of rapid instrumental methods to interpret the evolution of sensory characteristics.

Detection of Ovarian Cancer through Exhaled Breath by Electronic Nose: A Prospective Study.

BACKGROUND: Diagnostic methods for the early identification of ovarian cancer (OC) represent an unmet clinical need, as no reliable diagnostic tools are available. Here, we tested the feasibility of electronic nose (e-nose), composed of ten metal oxide semiconductor (MOS) sensors, as a diagnostic tool for OC detection. METHODS: Women with suspected ovarian masses and healthy subjects had volatile organic compounds analysis of the exhaled breath using e-nose. RESULTS: E-nose analysis was performed on breath samples collected from 251 women divided into three groups: 86 OC cases, 51 benign masses, and 114 controls. Data collected were analyzed by Principal Component Analysis (PCA) and K-Nearest Neighbors' algorithm (K-NN). A first 1-K-NN (cases vs. controls) model has been developed to discriminate between OC cases and controls; the model performance tested in the prediction gave 98% of sensitivity and 95% of specificity, when the strict class prediction was applied; a second 1-K-NN (cases vs. controls + benign) model was built by grouping the non-cancer groups (controls + benign), thus considering two classes, cases and controls + benign; the model performance in the prediction was of 89% for sensitivity and 86% for specificity when the strict class prediction was applied. CONCLUSIONS: Our preliminary results suggested the potential role of e-nose for the detection of OC. Further studies aiming to test the potential adoption of e-nose in the early diagnosis of OC are needed.

A modified mid-level data fusion approach on electronic nose and FT-NIR data for evaluating the effect of different storage conditions on rice germ shelf life.

Evaluating the possibility of extending shelf life of rice germ (a by-product of rice milling process) by reducing water activity in combination with storage atmosphere packaging, without any heat treatment, is the aim of the present study. Samples at different water activities (0.55, 0.45 and 0.36) were packed in air, argon or under vacuum, and stored at 27 °C for 150 days. To the aim, a non-targeted approach was applied by means of an FT-NIR spectrometer in reflectance with a rotating sample holder and a portable electronic nose, equipped with 10 non-specific sensors. For understanding the impact of the factors under study on the rice germ shelf life, a modified mid-level data fusion approach was applied to enhance the information most correlated with time. Moreover, Principal Component Analysis was applied on fused data to follow samples evolution during storage and identify different clusters according to the storage conditions. The rice germ case study allowed to better understand the information captured by the non-specific sensors: a 2D correlation map was developed combining the e-nose data with the NIR spectral information, highlighting relationships among NIR absorption bands and classes of chemical compounds inducing e-nose responses. A data fusion approach highlighted the importance of water activity on rice germ storage, while no interesting differences were ascribable to storage atmosphere packaging systems. In terms of correlation, the sensors could be divided in two groups, negatively inter-correlated: sensors ascribable to aromatic compounds (WC) and correlated with the NIR band around 4800-4900 cm-1 (N-H bending of primary amides, typical for peptides coming from protein hydrolysis); broad-range response sensors (WS), linked with the NIR band at 5128 cm-1 (second overtone of CO stretching of esters).

E-nose, e-tongue and e-eye for edible olive oil characterization and shelf life assessment: A powerful data fusion approach.

The aim of this work was to investigate the applicability of e-senses (electronic nose, electronic tongue and electronic eye) for the characterization of edible olive oils (extra virgin, olive and pomace) and for the assessment of extra virgin olive oil and olive oil quality decay during storage at different temperatures. In order to obtain a complete description of oil samples, physico-chemical analyses on quality and nutritional parameters were also performed. Data were processed by PCA and a targeted data processing flow-sheet has been applied to physico-chemical and e-senses dataset starting from data pre-processing introducing an innovative normalization method, called t0 centering. On e-senses data a powerful mid-level data fusion approach has been employed to extract relevant information from different analytical sources combining their individual contributions. On physico-chemical data, an alternative approach for grouping extra virgin olive oil and olive oil samples on the basis of their freshness was applied and two classes were identified: fresh and oxidized. A k-NN classification rule was developed to test the performance of e-senses to classify samples in the two classes of freshness and the average value of correctly classified samples was 94%. Results demonstrated that the combined application of e-senses and the innovative data processing strategy allows to characterize edible olive oils of different categories on the basis of their sensorial properties and also to follow the evolution during storage of extra-virgin olive oil and olive oil sensorial properties thus assessing the quality decay of oils.

Effect of low-protein diets in heavy pigs on dry-cured ham quality characteristics.

The present work aimed at evaluating if heavy pig low-protein diets balanced for amino acid (AA) profile affect the quality characteristics of dry cured hams. To the aim, 40 hams obtained by Italian Duroc×Italian Large White pigs fed three different dietary crude protein and indispensable AA levels were compared with those obtained by a conventional Parma ham Protected Designation of Origin diet (C). No physico-chemical (aw, pH), chemical (gross composition, NaCl, lipid peroxidation, non-protein nitrogen, total volatile bases) or sensory characteristics of hams were systematically affected by the administered diet, animal sex or their interaction with the exception of total and subcutaneous fat (the latter measured by an image analysis procedure). Considering gilts, low-protein diets resulted in samples with higher fat content and subcutaneous fat thickness with respect to hams obtained with C diet. In conclusion, low protein diets in the finishing phase of pig breeding could reduce the environmental impact due to nitrogen excretion without significantly affecting ham quality.

Characterization of Whole Grain Pasta: Integrating Physical, Chemical, Molecular, and Instrumental Sensory Approaches.

The consumption of whole-grain food-including pasta-has been increasing steadily. In the case of whole-grain pasta, given the many different producers, it seems important to have some objective parameters to define its overall quality. In this study, commercial whole-grain pasta samples representative of the Italian market have been characterized from both molecular and electronic-senses (electronic nose and electronic tongue) standpoint in order to provide a survey of the properties of different commercial samples. Only 1 pasta product showed very low levels of heat damage markers (furosine and pyrraline), suggesting that this sample underwent to low temperature dry treatment. In all samples, the furosine content was directly correlated to protein structural indices, since protein structure compactness increased with increasing levels of heat damage markers. Electronic senses were able to discriminate among pasta samples according to the intensity of heat treatment during the drying step. Pasta sample with low furosine content was discriminated by umami taste and by sensors responding to aliphatic and inorganic compounds. Data obtained with this multidisciplinary approach are meant to provide hints for identifying useful indices for pasta quality. PRACTICAL APPLICATION: As observed for semolina pasta, objective parameters based on heat-damage were best suited to define the overall quality of wholegrain pasta, almost independently of compositional differences among commercial samples. Drying treatments of different intensity also had an impact on instrumental sensory traits that may provide a reliable alternative to analytical determination of chemical markers of heat damage in all cases where there is a need for avoiding time-consuming procedures.

Soybean-Enriched Snacks Based on African Rice.

Snacks were produced by extruding blends of partially-defatted soybean flour with flours from milled or parboiled African-grown rice. The interplay between composition and processing in producing snacks with a satisfactory sensory profile was addressed by e-sensing, and by molecular and rheological approaches. Soybean proteins play a main role in defining the properties of the protein network in the products. At the same content in soybean flour, use of parboiled rice flour increases the snack's hardness. Electronic nose and electronic tongue discriminated samples containing a higher amount of soybean flour from those with a lower soybean flour content.

Polymer composites containing gated mesoporous materials for on-command controlled release.

Polyamidic nanofibrous membranes containing gated silica mesoporous particles, acting as carriers, are described as novel hybrid composite materials for encapsulation and on-command delivery of garlic extracts. The carrier system consists of MCM-41 solids functionalized in the outer surface, with linear polyamines (solid P1) and with hydrolyzed starch (solid P2), both acting as molecular gates. Those particles were adsorbed on electospun nylon-6 nanofibrous membranes yielding to composite materials M1 and M2. FE-SEM analysis confirmed the presence of particles incorporated on the nylon nanofibers. The release of the entrapped molecules (garlic extract) from the P1, P2, M1, and M2 materials was evaluated using cyclic voltammetry measurements. Electrochemical studies showed that at acidic pH P1 and M1 were unable to release their entrapped cargo (closed gate), whereas at neutral pH both materials release their loading (open gate). Dealing with P2 and M2 materials, in the absence of pancreatin a negligible release is observed (closed gate), whereas in the presence of enzyme the load is freely to diffuse to the solution. These newly developed composite nanomaterials, provide a homogeneous easy-to-handle system with controlled delivery and bioactive-protective features, having potential applications on pharmacology, medical and engineering fields.