Memes Research Articles

Morphological, physiological, and biochemical responses of some olive tree cultivars to low temperature stress

Morphological, physiological, and biochemical responses of some olive tree cultivars to low temperature stress

Predicting oil accumulation by fruit image processing and linear models in traditional and super high-density olive cultivars

The paper focuses on the seasonal oil accumulation in traditional and super-high density (SHD) olive plantations and its modelling employing image-based linear models. For these purposes, at 7-10-day intervals, fruit samples (cultivar Arbequina, Fasola, Frantoio, Koroneiki, Leccino, Maiatica) were pictured and images segmented to extract the Red (R), Green (G), and Blue (B) mean pixel values which were re-arranged in 35 RGB-derived colorimetric indexes (CIs). After imaging, the samples were crushed and oil concentration was determined (NIR). The analysis of the correlation between oil and CIs revealed a differential hysteretic behavior depending on the covariates (CI and cultivar). The hysteresis area (Hyst) was then quantified and used to rank the CIs under the hypothesis that CIs with the maximum or minimum Hyst had the highest correlation coefficient and were the most suitable predictors within a general linear model. The results show that the predictors selected according to Hyst-based criteria had high accuracy as determined using a Global Performance Indicator (GPI) accounting for various performance metrics (R2, RSME, MAE). The use of a general linear model here presented is a new computational option integrating current methods mostly based on artificial neural networks. RGB-based image phenotyping can effectively predict key quality traits in olive fruit supporting the transition of the olive sector towards a digital agriculture domain.

A novel integrated approach for quantifying the convergence of disruptive technologies from science to technology

With rapid developments in science and technology, knowledge transfer from science to technology and technology convergence from different fields are accelerating. Technology convergence has become a main source of disruptive technologies (DTs). To facilitate enterprise R&D strategic decision-making and government innovation policies formulation, it is necessary to quantify the convergence processes of DTs and understand the DTs' emergence characteristics from science to technology. Existing research on technology convergence measurement mainly used patent citation information, patent co-classification analysis, and text mining. However, since these studies have limited analysis of the sources and causes of technology convergence from the perspective of knowledge memes, resulting in insufficient revelation of the processes and characteristics of DTs' emergence. Knowledge meme theory helps to reveal the relationships between knowledge diffusion, knowledge convergence, and technology convergence. Therefore, in this paper, we proposed a research framework for quantifying the convergence of DTs from science to technology. In this framework, we analyzed the knowledge diffusion and technology convergence of DTs from science to technology based on knowledge meme theory. We also integrated patent citation analysis, text mining, and cascade network models to quantitatively measure knowledge diffusion and technology convergence characteristics. We tried to understand the generation mechanisms of DTs from the perspective of technology convergence. We took smartphones as a case study to verify the framework's validity and flexibility. This paper provides a novel approach for quantifying the convergence of DTs from science to technology, which can help us to understand the emergence and development trends of DTs. This paper will also be of interest to smartphone technology R&D experts.

Unravelling Different Water Management Strategies in Three Olive Cultivars: The Role of Osmoprotectants, Proteins, and Wood Properties

Understanding the responses of olive trees to drought stress is crucial for improving cultivation and developing drought-tolerant varieties. Water transport and storage within the plant is a key factor in drought-tolerance strategies. Water management can be based on a variety of factors such as stomatal control, osmoprotectant molecules, proteins and wood properties. The aim of the study was to evaluate the water management strategy under drought stress from an anatomical and biochemical point of view in three young Italian olive cultivars (Giarraffa, Leccino and Maurino) previously distinguished for their physiological and metabolomic responses. For each cultivar, 15 individuals in pots were exposed or not to 28 days of water withholding. Every 7 days, the content of sugars (including mannitol), proline, aquaporins, osmotins, and dehydrins, in leaves and stems, as well as the chemical and anatomical characteristics of the wood of the three cultivars, were analyzed. ‘Giarraffa’ reduced glucose levels and increased mannitol production, while ‘Leccino’ accumulated more proline. Both ‘Leccino’ and ‘Maurino’ increased sucrose and aquaporin levels, possibly due to their ability to remove embolisms. ‘Maurino’ and ‘Leccino’ accumulated more dehydrins and osmotins. While neither genotype nor stress affected wood chemistry, ‘Maurino’ had a higher vessel-to-xylem area ratio and a larger hydraulic diameter, which allows it to maintain a high transpiration rate but may make it more susceptible to cavitation. The results emphasized the need for an integrated approach, highlighting the importance of the relative timing and sequence of each parameter analyzed, allowing, overall, to define a “strategy” rather than a “response” to drought of each cultivar.

Susceptibility of olive cultivars and selections to Colletotrichum species causing anthracnose in Spain.

Anthracnose, the most critical fruit disease affecting olive crops, necessitates the evaluation of the susceptibility of traditional and new varieties. In Spain and Portugal, Anthracnose is caused by several Colletotrichum species, with C. godetiae and C. nymphaeae being dominant and C. acutatum and C. fioriniae being secondary. This study explores the susceptibility of fruits from an F1 progeny resulting from a cross between 'Picual' (resistant) and 'Arbequina' (moderately susceptible) cultivars to C. godetiae. While most genotypes showed resistance levels comparable to their parents, seven showed a 50% reduction in disease severity compared to 'Picual.' The normal distribution of genotypes' response to the pathogen suggests a complex resistance mechanism. Furthermore, we assessed the susceptibility of four traditional cultivars, two new cultivars ('Sikitita-2' and 'Martina'), and five advanced selections (pre-commercial genotypes) to C. godetiae and C. nymphaeae. Despite the significant interaction between the olive genotype and Colletotrichum species in this experiment, the new cultivars and advanced selections were classified as susceptible or moderately susceptible against both species. A subsequent analysis of the interaction between 'Picual' (resistant) and 'Hojiblanca' (susceptible) fruits with the four mentioned Colletotrichum species revealed significant differences among cultivars but no interaction between genotype and pathogen species. Colletotrichum species were categorized as follows: i) C. godetiae and C. nymphaeae as highly virulent, ii) C. acutatum as moderately virulent, and iii) C. fioriniae as weakly virulent. Finally, C. nymphaeae exhibited an enhanced ability to infect and develop acervuli in olive leaves, potentially serving as an inoculum source for this species. The absence of a correlation between leaf and fruit susceptibilities to the pathogen suggests differences in resistance mechanisms. In conclusion, this study provides valuable insights into the complex interactions between olive genotype and Colletotrichum species, essential for cultivar selection and understanding the disease cycle.

Artificial intelligence tools and concepts give access to authenticity and quality information in Brazilian olive oil volatilome

Brazil is the world's second largest importer of olive oil and stared to produce its own oil quite recently in two distinct geographic areas. The production is still very small, and studies regarding oil composition are scarce. Determination of discriminant differences are useful to support appeals regarding origin indication and to detect fraud and adulteration with oils from other countries. In this work the Brazilian extra virgin olive oils (EVOOs) volatilome is explored by Artificial Intelligence (AI) tools developed on multiple headspace solid-phase microextraction (MHS-SPME) combined with comprehensive 2D gas chromatography-mass spectrometry and flame ionization detection (GC×GC-MS/FID) data. Using MHS-SPME, external standard calibration, and FID predicted relative response factors (RRF), the accurate quantification of 51 informative volatile compounds was carried out and the odorants responsible for key-positive sensory attributes were used to generate distinctive aroma blueprints aligned with the AI smelling based on sensomics. As authenticity and origin assessment decision-making tool, augmented visualization by computer vision was applied on volatilome 2D fingerprints. By this approach, extra-virgin olive oil samples (n=35), from two olive cultivars (Arbequina and Koroneiki) harvested in the main producing regions in Brazil (Rio Grande do Sul and Serra da Mantiqueira) in 2021 and 2022, were effectively discriminated and mislabeled products regarding their geographical origin were, for the first time, promptly identified.

Analysis of Genetic Diversity of Some Olive Cultivars Olea Europoea L. Using ISSR, SSR

In the current investigation, the genetic relations, and the genetic dimension of seven olive varieties (Olea europaea L.) were identified using, ISSR, and SSR markers. The study involved uses leaves from different samples for DNA extraction. The DNA amount ranged from 150 to 400 micrograms with purity ranging between 1.6 to 1.9. Agarose gel electrophoresis is applied to evaluate PCR reaction success. The ISSR marker, which used 4 primers, showed different results for the multiplication. Various bands were observed that differed from each other, resulting in a total of 93 bands - 2 general and 91 different. The primer also distinguished unique bands, with 4 unique bands and 7 absent bands. The primer with the highest molecular size (1500bp) was UBC-817, while the lowest molecular volume (200bp) was observed in the UBC-826 primer. The marker results indicated that the two types, Suranie (3) and Frantoio (4), had the lowest hereditary dimension of (0.030). The Frantoio and Santacatrina varieties showed the highest genetic difference, with a value of 0.622. According to the genetic relationship analysis, there were three main groups. The first group consisted of a single category (5), while There were two subgroups in the second group, B1 and B2. Subgroup B1 had only one category, while the rest of the categories were in Subgroup B2.. Even though these markers use different mechanisms to detect variance and genome coverage, they complement each other. Moreover, five SSR markers were used in this study to describe seven olive cultivars and analyze their genetic relationship. Four out of five primers showed positive results, while one was not present. The SSR markers were effective in identifying the similarity of collected species, as they are specialized indicators ISSR markers.

Unraveling the genetic basis of oil quality in olives: a comparative transcriptome analysis.

The balanced fatty acid profile of olive oil not only enhances its stability but also contributes to its positive effects on health, making it a valuable dietary choice. Olive oil's high content of unsaturated fatty acids and low content of saturated fatty acids contribute to its beneficial effects on cardiovascular diseases and cancer. The quantities of these fatty acids in olive oil may fluctuate due to various factors, with genotype being a crucial determinant of the oil's quality. This study investigated the genetic basis of oil quality by comparing the transcriptome of two Iranian cultivars with contrasting oil profiles: Mari, known for its high oleic acid content, and Shengeh, characterized by high linoleic acid at Jaén index four. Gas chromatography confirmed a significant difference in fatty acid composition between the two cultivars. Mari exhibited significantly higher oleic acid content (78.48%) compared to Shengeh (48.05%), while linoleic acid content was significantly lower in Mari (4.76%) than in Shengeh (26.69%). Using RNA sequencing at Jaén index four, we analyzed genes involved in fatty acid biosynthesis. Differential expression analysis identified 2775 genes showing statistically significant differences between the cultivars. Investigating these genes across nine fundamental pathways involved in oil quality led to the identification of 25 effective genes. Further analysis revealed 78 transcription factors and 95 transcription binding sites involved in oil quality, with BPC6 and RGA emerging as unique factors. This research provides a comprehensive understanding of the genetic and molecular mechanisms underlying oil quality in olive cultivars. The findings have practical implications for olive breeders and producers, potentially streamlining cultivar selection processes and contributing to the production of high-quality olive oil.

Experimental Infection of California Ripe Olive Cultivars with Xylella fastidiosa Subspecies pauca De Donno and Acquisition by Glassy-Winged Sharpshooter

Strains of Xylella fastidiosa subspecies pauca can infect olive trees, and an introduction of this pathogen has caused significant damage to the olive industry in Europe. Although this subspecies is not known to be present in North America, the environment, plant hosts, and insect vectors in the United States olive-growing regions (mainly California) are conducive to X. fastidiosa spread and disease damage. This study evaluated several risk factors for X. fastidiosa disease in the California olive industry, including infection of the common cultivars and acquisition by insect vectors. Olive cultivars Manzanillo, Sevillano, and Mission all exhibited disease symptoms after inoculation with X. fastidiosa strain De Donno obtained from the olive disease outbreak in southern Italy. Glassy-winged sharpshooters were able to acquire X. fastidiosa De Donno from infected olive plants as soon as 30 days after plant inoculation. This information is valuable for risk assessment and disease management planning in the event of a future introduction of olive-pathogenic strains of X. fastidiosa to the United States. [Formula: see text] The author(s) have dedicated the work to the public domain under the Creative Commons CC0 “No Rights Reserved” license by waiving all of his or her rights to the work worldwide under copyright law, including all related and neighboring rights, to the extent allowed by law, 2024.

MORPHOLOGICAL AND YIELD-RELATED POMOLOGICAL CHARACTERIZATION OF INTRODUCED OLIVE (OLEA EUROPEA) CULTIVARS IN RAINFED AREA OF POTHOWAR PUNJAB

This study aims at pomological characterizing of 09 olive cultivars planted in the field area of Barani Agricultural Research Institute (BARI), Chakwal to estimate genetic variability in Ottobratica, Hamdi, FS-17, Gerboi, Arbequina, Persia, Nabali, Koroneiki and Earlik. Following pomological traits: fruit and stone weight (g), fruit and stone size (cm), fruit and stone shape index (length/width) and flesh to stone ratio were studied. Data for studied traits were collected in 2019 according to the International olive council descriptor. A significant genetic difference was noticed in the morphological characteristics of both fruit and stone. Different pomological characters were expressed by each cultivar. A wide range of variation was noticed in fruit weight (1.33-5.57g), stone weight (0.20-0.63g) and flesh/stone ratio (0.90-4.96). Based on their fruit shape, studied cultivars were classified into two groups i.e., ovoid and elongate. However, no significant difference was recorded for the stone shape, as all the studied cultivars had the same elongated stone shape. Concerning the fruit size, high fruit size (4-6g) was observed in FS-17, Hamdi, Earlik and Persia whereas Koroneiki, Nabali and Gerboi had the smallest ones (>2g). Based on our results, Earlik, Hamdi and FS-17 are suggested to be more appropriate for table olive production. Thus, an evaluation of genetic diversity through this study can help in the varietal development of olive for table and oil purposes.

Grafting Effect of Different Olive Cultivars on “Barnea” Olive (K18) at Al-Karak Area

The experiment was conducted at Al-Rabba Agricultural Research Station (31°27′57.34″N, 35°740′984.0″E), North to Karak city. It was designed to study the impact of time of grafting of different olive cultivars using K18 olive as rootstock for them. Seven olive cultivars were selected (Nabali Baladi, Frontoio, Grosadi, Rassei, Manzanillo, Nasohi and K18). The K18 cultivar was used as the control, at which scion of K18 grafted on the K18 rootstock. Two factors, olive cultivars in addition to two different grafting times, late January and mid-March, were arranged in randomized complete block design replicated three times. Results showed that, different times of grafting significantly affected all parameters studied, except number of leaves. Significant differences were observed among cultivars for all variables studied, except for number of sprouts per grafting. The time of grafting Results showed that maximum sprouting percentage (73.8%), number of sprouts (4.1), shoot length (12.23 cm), shoot diameter (2.56 mm), leaves per shoot (17.05) and minimum days to sprouting (26.6) were recorded in olive trees grafted in mid-March. While trees grafted on late January take higher number of days to sprout (32.7), minimum sprouting percentage (67.7%) and shoot diameter (2.19 mm). The cultivars performance results showed that maximum sprouting percentage (71.8%), shoot length (11.48 cm), leaves per shoot (17.43), lower days to sprouting (28.5) and shoot diameter (2.06 mm) were attained by the cultivar Nabali Baladi, while Rassei showed lower sprouting percentage (62.7%), leaves per shoot (12.80) and maximum days to sprouting (30.1). It was concluded that mid-March is the optimum time for grafting of olive cultivars, specifically Nabali Baladi in this area.

Hermaphrodite Flower Ratios and Fruit Drop in Different Olive Cultivars

Hermaphrodite Flower Ratios and Fruit Drop in Different Olive Cultivars

Effects of classical and organomineral fertilizer applications on pollen quality and quantity in gemlik olive cultivar

Olive is one of the important plants worldwide in terms of economic and cultural conditions. It is used in fresh consumption, olive oil, cosmetic and pharmaceutic fields and unique numinous plants. Olive can maintain its life for many years even in barren conditions but for an economic cultivation, fertile and preferred cultivars should be used in orchards and optimum maintenance conditions should be provided. At the same time the climate change is also convert the usual behavior of the plants. This study aims to determine the effects of classic and organomineral fertilizers on pollen quality and quantity parameters. In this study, classical fertilizers like Urea+MgSO4 and KNO3+H3BO3+ZnSO4 with Raykat Start, Raykat Growth and Fitomare organomineral fertilizers were sprayed foliarly before flowering on Gemlik olive cultivar and pollen studies were conducted on the flowers formed at full flowering. Within the study, effects of the treatments were evaluated on pollen viability and germination levels, the amount of pollen produced in one flower and the normally developed pollen ratio. As a result of this study, fertilization treatments positively affected pollen quality and quantity with regard to control treatment. In this context, the pollen viability level differed between 74.15% and 89.92%, the pollen germination level between 45.48% and 70.35% and pollen per flower was between 307.238 and 446.761. The lowest data were obtained from control treatments, while the highest were from Raykat group fertilizers. Especially, the 54% increase in pollen germination level with Raykat growth fertilization was one of the most important results of this study. In conclusion, it was determined that the foliar spray of organomineral fertilizers enhanced the pollen properties. Raykat Start, Raykat Growth and Fitomare organomineral fertilizers used in this study significantly increased pollen quality and quantity.

Nanostructure-assisted drought tolerance in olive trees (Olea europaea L.): the role of Fe2O3-graphitic carbon.

Olive trees are known as one of the most iconic crops in the world. Considering the increasing water deficit worldwide, implementing some profitable and empirical strategies can be inevitable upon exposure to drought stress. Therefore, the present study aimed at clarifying the beneficial role of exogenously foliar application of Fe2O3 modified carbon nitride nanostructures (control, FeSO4, C3N4 and Fe2O3/g-C3N4) to "Shengeh" olive cultivars grown at different watering levels (100, 75, and 50% ET) in two experimental years (2022 and 2023) and the pomological attributes, physiological and biochemical changes happening in the treated leaves and fruits were discussed. The results indicated that drought stress caused a significant decline in pomological attributes in this experiment, and treatments could remarkably make up for this damage. Overall, Fe2O3/g-C3N4 outperformed as compared FeSO4 and C3N4 alone, which were also efficacious in conferring tolerance to the water deficit stress. Conversely, severe drought stressed-olive fruits showed higher oil content percent in the fresh matter and water use efficiency (WUE) in oil by 30% and 52.5%, respectively, as an average of results of two years, and after Fe2O3/g-C3N4, these features in olive plants subjected to severe drought improved by an average of 35% over two years. Ca2+ and K+ in olive plants under severe drought stress declined by 50% and 83% in 2022 and 46% and 24% in 2023, while Na+ increased in the plants exposed to 50%ET stress by 48% and 57% in two successive experimental years respectively. The application of Fe2O3/g-C3N4 remarkably improved the contents of Ca2+ and K+ by 101.5% and 369%, respectively, as an average of two years. Conversely, this beneficial treatment led to a significant decline in Na+ levels by 30% in 2022 and 2% in 2023 under stressful conditions. Moreover, it decreased the 'osmolytes' content, caused a smaller decline in chlorophyll levels, and resulted in higher relative water content occurring in the treated olive leaves. The reduction of oxidative markers was a result of the increased enzymatic activity after the use of Fe2O3/g-C3N4. Therefore, this treatment is a promising strategy to achieve improved resistance in olive plants in the future.

Rhizobacterial diversity of Portuguese olive cultivars in the Douro valley and their potential as plant growth promoters.

This study investigated the bacterial communities in the rhizosphere of two traditional Portuguese olive cultivars, Cobrançosa and Negrinha de Freixo, in relation to soil properties. Additionally, we aimed to isolate and identify bacteria with potential for biocontrol and other plant growth-promoting traits from these rhizosphere communities. Bacterial communities in the olive rhizosphere were investigated using a metabarcoding approach and the soil physicochemical properties of the olive groves were also analyzed. Higher bacterial richness was associated with Negrinha de Freixo growing in soil with high organic matter content and water-holding capacity. In contrast, the soils of the Cobrançosa grove presented higher pH and electric conductivity. Negrinha de Freixo rhizosphere was enriched with ASVs (Amplicon Sequence Variants) belonging to Bacillus, Gaiella, Acidothermus, Bradyrhizobium, and uncultured Xanthobacteraceae. On the other hand, the Cobrançosa rhizosphere was characterized by higher relative abundance of Streptomyces and Sphingomonas. Bacterial isolation from the rhizosphere and screening for plant growth-promoting activities were also performed. Six bacteria strains, predominantly Bacillus isolated from Negrinha de Freixo, demonstrated antagonistic activities against the olive fungal pathogen Colletotrichum gloeosporoides and other plant growth promotion (PGP) traits. Our findings demonstrate that the structure of rhizosphere bacterial communities associated with olive trees is shaped by both plant cultivar and soil-related factors. The higher number of bacterial species in the rhizosphere of Negrinha de Freixo was related to a higher organic matter content and a greater abundance of isolates with plant growth promotion traits, particularly Bacillus strains.

Improving vegetative growth of transplants of two olive cultivars by foliar application of some organic extracts and chemical fertilizers.

Improving vegetative growth of transplants of two olive cultivars by foliar application of some organic extracts and chemical fertilizers.

Integrated Transcriptome and Metabolome Analysis Revealed the Key Role of the Flavonoid Biosynthesis in Olive Defense Against Alternaria alternata.

The olive tree is an important oil woody plant with high economic value, yet it is vulnerable to the attack of numerous fungi. The successful control of olive fungal diseases requires a comprehensive understanding of the disease resistance mechanisms in plants. Here, we isolated Alternaria alternata from the diseased leaves of olive plants, and screened a resistant ("Leccino") and susceptible ("Manzanilla de Sevilla") cultivar from eight olive cultivars to explore their resistance mechanisms. Transcriptomic and metabolomic analyses identified the flavonoid biosynthesis as a key defense pathway against A. alternata. Five important transcription factors associated with flavonoid biosynthesis were also determined. The overexpression of OeWRKY40 significantly enhanced the disease resistance of the susceptible cultivar and upregulated the expression of genes involved in flavonoid biosynthesis and the accumulation of related metabolites. LUC assays further proved that OeWRKY40 can activate the expression of OeC4H. These results help to better clarify the molecular mechanisms of flavonoid biosynthesis against A. alternata. Our study provides key information for further exploration of the molecular pathways of olive plants and their resistance to fungi, an important factor for molecular breeding and utilization of resistant cultivars.

Phytochemical Characterization of Two New Olive Oil Genotypes Growing in Southern Tunisia.

This research can be considered as the first complete survey for the valorization of new olive genotypes cultivated in the South-East of Tunisia as well as their oils. The study aimed to characterize the phytochemical composition of virgin olive oil produced from two olive cultivars, namely Nourgou and Gousalani. The pomological characterization of fruits, the quality criteria and the phytochemical profile were quantified. Additionally, antioxidant activity was evaluated using Ferric reducing antioxidant power (FRAP) and Oxygen radical absorbance capacity (ORAC) tests to also obtain a bioactive characterization of these monovarietal olive oils. The obtained results revealed that the analyzed olive oils samples can be classified into Extra Virgin category (EVOO) according to the regulated physicochemical characteristics. Our findings showed a significant variability in the chemical parameters of the analyzed EVOO likely associated with the genetic potential, mainly for chlorophylls contents (1.37-1.64 mg/kg), in carotenoids pigments (3.97-10.86 mg/kg), in α-tocopherol (175.59-186.87 mg/kg), in sterols (1036.4-1931.4 mg/kg) in oleic acid (65.33-68.73%), in palmitic acid (C16:0) (13.32-17.48%), in linoleic acid (C18:2) (11.06-13.47%). Additionally, the HPLC-MS/MS analysis showed that the two EVOOs analyzed contained appreciable amounts of total polyphenols, ranging from 348.03 up to 516.16 mg/kg, in Nourgou and Gousalani oils, respectively. Regarding the individual phenolic compounds, the EVOO samples were mainly characterized by phenolic alcohols, phenolic acids, secoiridoids, verbascoside, flavonoids and phenolic aldehydes. The prevalent simple phenolics detected were secoiridoids with the dominance of the oleuropein aglycone in Gousalani oil. In addition, findings from in vitro antioxidant assays (FRAP and ORAC) revealed that the two studied oils possessed a powerful antiradical activity and a good reducing power capacity. In conclusion, these new EVOOs exhibited a superior quality compared to other Tunisian varieties, considering their antiradical activity and reducing power capacity.

Olive Oil (Royal Cultivar) from Mill Obtained by Short Time Malaxation and Early Ripening Stage.

The olive oil from the Royal cultivar has not been studied in depth, especially its relationship between analytical and sensory parameters. Currently, it is a minority cultivar, but due to its excellent organoleptic properties, it is constantly growing. The research objective is to obtain excellent-quality olive oil from the Royal cultivar at an industrial extraction plant and characterize the oil sensory and analytically. For this purpose, three important factors were set: very early olives; very low-time olive paste malaxation; and environmental temperature. The analytical parameters studied were volatile and phenolic compounds, fatty acids, photosynthetic pigments, and other quality parameters. Fourteen phenolic compounds were identified and found in significantly higher concentrations in Royal olive oil, including the oleacein compound. Moreover, volatile compounds from the LOX pathway, such as hexenal, (E)-2-hexenal, and (Z)-3-hexen-1-ol, had significantly higher concentrations, which were related to organoleptic characteristics: very fruity, not very spicy, and very low bitterness. The highest values obtained were 74.98% extraction efficiency at 30 min; 71.31 mg/kg chlorophyll content at 30 min; 156.38 mg/kg phenolic compound at 30 min; 18.98 mg/kg volatile compounds at 15 min; and better organoleptic characteristics at 15 min. The oil extraction efficiency was lower than that of other olive cultivars; nevertheless, the content of volatile compounds is higher.

An Evaluation of Different Sweet Olive Cultivars with Different Ripening Degrees Grown in the Puglia Region, Southeastern Italy

Some olive cultivars grown in southeastern Italy are characterized by the production of olives with a reduced level of bitterness. They are known as sweet olive cultivars and fruits are usually consumed directly or cooked without any debittering process, offering either health benefits to consumers, thanks to the high content of antioxidants, or an economic benefit to farmers for their higher price with respect to both table and oil olives. This study evaluates and compares the organoleptic, pomological, chemical, and physical parameters of seven sweet olive cultivars at different ripening degrees in the Puglia region over 8 weeks of maturity stage for two consecutive seasons (2022 and 2023). The organoleptic evaluation was performed by a restricted panel of usual consumers/experts of sweet olives. The results showed a higher preference for the olive cultivars locally named Triggiano Dolce, Cerasella, and Mele. Significant differences in weight, length, and width of the fruits were observed based on both cultivar and year. The phenolic composition of olive cultivars was significantly affected by both cultivar and harvest year, with Cazzinicchio and Cellina di Nardò having the highest total polyphenols. The analysis of water fraction extracted from olive samples by liquid chromatography coupled with mass spectrometry led to the identification of eleven compounds belonging to the secoiroids, phenylpropanoids, phenylethanolids, and flavonoids classes. The comparison of these compounds among the studied cultivars highlighted significant differences.