Aroma profile and volatile composition of black ripe olives (Manzanilla and Hojiblanca cultivars)

Effects of different drying methods on Rubus chingii Hu fruit during processing

In this study, the dried fruits of Rubus chingii Hu (Chinese name: Fu-Pen-Zi; FPZ) were processed and dried by three methods-in the shade, the sun, and the oven. The composition regarding the standard ingredient, color, and antioxidant capacities were investigated pro- and post-processing. The technique of headspace-solid-phase-microextraction-gas-chromatography-mass spectrometry (HS-SPME-GC-MS) and flavoromics were used to analyze the flavor-conferring metabolites of FPZ. The results obtained revealed that the highest use value and antioxidant capacities were detected in the FPZ fruits processed and dried in the shade. A total of 358 metabolites were detected from them mainly consisting of terpenoids, heterocyclic compounds, and esters. In differential analysis, the down-regulation of the metabolites was much greater than their up-regulation after all three drying methods. In an evaluation of the characteristic compounds and flavors produced after the three methods, there were variations mainly regarding the green and fruity odors. Therefore, considerable insights may be obtained for the development of novel agricultural methods and applications in the pharmaceutical and cosmetic industries by analyzing and comparing the variations in the chemical composition detected pre- and post-processing of the FPZ fruits. This paper provides a scientific basis for quality control in fruits and their clinical applications.

A machine learning method for juice human sensory hedonic prediction using electronic sensory features

This study proposed a method that combines fused electronic sensory analysis technology with artificial neural network to predict the human sensory hedonic of fruit juice. Quantitative descriptive analysis (QDA) and the scoring test method were utilized for human sensory evaluation. The first step involved modeling the fused e-sensory features with human sensory attributes, followed by establishing a fitting model of human sensory attributes and acceptance. The R2 and RMSE values obtained were 0.77 and 0.42 (QDA method), and 0.63 and 0.63 (scoring test method). Finally, the relationship between the fusion e-sensory features and the human sensory hedonic was established. Model-1 achieved an R2 of 0.95 and an RMSE of 0.04, while model-2 achieved an R2 value of 0.88 and an RMSE value of 0.21. This study demonstrates the potential of fusing e-sensory technologies to replace human senses, which may lead to the development of devices with simultaneous multiple senses.

Effect of Calcium Salts on the Firmness and Physicochemical and Sensorial Properties of Iranian Black Olive Cultivars

Black olive has become one of the most prestigious olives processed in the olive industry, and its processing has been increased recently in different countries. The firmness of black olives may be changed by the processing methods, fermentation, and solution salts. In this study, the employment of CaCl2, Ca-acetate, and Ca-lactate during the processing of some Iranian black olive cultivars, including Mari, Zard, Rowghani, Shengeh, Dakal, Dezful, and Fishomi, was evaluated in terms of physicochemical and phenolic compounds and textural attributes. The results showed that Ca-lactate improved the firmness of the Mari cultivar from 1455 to 1765 N/100 g in the pitted olive, and the same trend was obtained for the other cultivars. Ca-acetate improved the black shiny color of the Mari cultivar from 4.36 to 4.85 and the sensorial properties of the black olives, including gustatory and kinesthetic sensations, were improved by using a Ca-lactate solution. The application of calcium salts in the salt-free preservation solutions imparted neither bitterness to the olives nor discoloration. The highest amounts of acid (1.42-1.56%), fructose to mannitol ratio (1-1.2), and phenolic compounds (955-963 mg/kg) were found for the Zard cultivar. Furthermore, the residual content of oleuropein was higher when CaCl2 was employed (357 mg/kg). All of the calcium salts improved the firmness of the black olives, although the maximum firmness was observed for the Ca-lactate. Consequently, the formation of a black shiny color is related to the diffusion of phenolic compounds; however, this needs further investigation to determine which kind of phenolic compound is responsible for its black color.

Authentication and Chemometric Discrimination of Six Greek PDO Table Olive Varieties through Morphological Characteristics of Their Stones

Table olives, the number one consumed fermented food in Europe, are widely consumed as they contain many valuable ingredients for health. It is also a food which may be the subject of adulteration, as many different olive varieties with different geographical origin, exist all over the word. In the present study, the image analysis of stones of six main Greek protected designation of origin (PDO) table olive varieties was performed for the control of their authentication and discrimination, with cv. Prasines Chalkidikis, cv. Kalamata Olive, cv. Konservolia Stylidas, cv. Konservolia Amfissis, cv. Throuba Thassos and cv. Throuba Chios being the studied olive varieties. Orthogonal partial least square discriminant analysis (OPLS-DA) was used for discrimination and classification of the six Greek table olive varieties. With a 98.33% of varietal discrimination, the OPLS-DA model proved to be an efficient tool to authentify table olive varieties from their morphological characteristics.

Volatile Composition of Industrially Fermented Table Olives from Greece

Table olives represent one of the most important fermented products in Greece. Their highly appreciated flavor is directly associated with the volatile composition. However, extensive data on the volatile profile of table olives from Greek cultivars are scarce in the literature. For this reason, the volatile components of industrially fermented table olives from Kalamata, Conservolea and Halkidiki cultivars grown in different geographical areas within Greece were determined using headspace solid-phase microextraction combined with gas chromatography–mass spectrometry. More than 100 volatile compounds were identified and distributed over different chemical classes. All samples were rich in esters, alcohols and acids, whereas the samples of cv. Halkidiki were also characterized by increased levels of volatile phenols. Both qualitative and quantitative differences were observed, which resulted in the discrimination of the table olives according to olive cultivar and growing location. To the best of our knowledge, this is the first systematic study on the volatile profiles of table olives from Greek cultivars that also highlights the pronounced effect of olives’ growing location.

Authentication of Greek PDO Kalamata Table Olives: A Novel Non-Target High Resolution Mass Spectrometric Approach

Food science continually requires the development of novel analytical methods to prevent fraudulent actions and guarantee food authenticity. Greek table olives, one of the most emblematic and valuable Greek national products, are often subjected to economically motivated fraud. In this work, a novel ultra-high-performance liquid chromatography–quadrupole time of flight tandem mass spectrometry (UHPLC-QTOF-MS) analytical method was developed to detect the mislabeling of Greek PDO Kalamata table olives, and thereby establish their authenticity. A non-targeted screening workflow was applied, coupled to advanced chemometric techniques such as Principal Component Analysis (PCA) and Partial Least Square Discriminant Analysis (PLS-DA) in order to fingerprint and accurately discriminate PDO Greek Kalamata olives from Kalamata (or Kalamon) type olives from Egypt and Chile. The method performance was evaluated using a target set of phenolic compounds and several validation parameters were calculated. Overall, 65 table olive samples from Greece, Egypt, and Chile were analyzed and processed for the model development and its accuracy was validated. The robustness of the chemometric model was tested using 11 Greek Kalamon olive samples that were produced during the following crop year, 2018, and they were successfully classified as Greek Kalamon olives from Kalamata. Twenty-six characteristic authenticity markers were indicated to be responsible for the discrimination of Kalamon olives of different geographical origins.

Table Olives: An Overview on Effects of Processing on Nutritional and Sensory Quality

Table olives are a pickled food product obtained by a partial/total debittering and subsequent fermentation of drupes. Their peculiar sensory properties have led to a their widespread use, especially in Europe, as an appetizer or an ingredient for culinary use. The most relevant literature of the last twenty years has been analyzed in this review with the aim of giving an up-to-date overview of the processing and storage effects on the nutritional and sensory properties of table olives. Analysis of the literature has revealed that the nutritional properties of table olives are mainly influenced by the processing method used, even if preharvest-factors such as irrigation and fruit ripening stage may have a certain weight. Data revealed that the nutritional value of table olives depends mostly on the balanced profile of polyunsaturated and monounsaturated fatty acids and the contents of health-promoting phenolic compounds, which are best retained in natural table olives. Studies on the use of low salt brines and of selected starter cultures have shown the possibility of producing table olives with an improved nutritional profile. Sensory characteristics are mostly process-dependent, and a relevant contribute is achieved by starters, not only for reducing the bitterness of fruits, but also for imparting new and typical taste to table olives. Findings reported in this review confirm, in conclusion, that table olives surely constitute an important food source for their balanced nutritional profile and unique sensory characteristics.