Analysis of natural colourant extracted from the pericarp of passion fruit

Integrated metabolomics and proteomics analysis of anthocyanin biosynthesis regulations in passion fruit (Passiflora edulis) pericarp

Anthocyanin is the primary color-developing component in the pericarp of the passion fruit. Although the pericarp of the passion fruit is anticipated to be a significant source of anthocyanin, however, information regarding anthocyanin biosynthesis in the passion fruit pericarp remains unexplored. Based on metabolomics analysis, a total of five anthocyanins were identified in the purple-skinned passion fruit pericarp, among which three anthocyanins, petunidin-3-O-arabinoside, geranylgeranyl-3,5-O-diglucoside, and petunidin-3-O-rutinoside, play key roles in the coloration of the passion fruit pericarp. Based on proteomics analysis, a total of nine differential proteins are involved in the flavonoid metabolic process, which involves the following chalcone isomerase, flavonol synthase and anthocyanin synthasein. These proteins play important regulatory roles in anthocyanin biosynthesis and are the key regulators in anthocyanin accumulation. qRT-PCR was used to identify nine structural genes (PePAL2, PePAL4, PeC4H1, Pe4CL5, Pe4CL6, Pe4CL7, PeCHS2, PeCHS3 and PeUFGT2) playing key regulatory roles in anthocyanin synthesis in purple passion fruit pericarp. This study is expected to lay a foundation for the subsequent exploration of the regulatory mechanism of anthocyanin biosynthesis and the functional identification of related genes in passion fruit pericarp, and also to provide data support for the in-depth utilization of passion fruit resources.

Phytochemistry, nutritional composition, health benefits and future prospects of Passiflora: A review

Passiflora, also known as "passion fruit", is widely grown in tropical and subtropical regions. It is not only eaten raw but is also widely used in processed foods. Various extracts, juices and isolated compounds show a wide range of health effects and biological activities, such as antioxidant, anti-inflammatory, sedative, and neuroprotective effects. In this review, we not only review the phytochemical properties of Passiflora but also highlight the potential of Passiflora for food applications and the use of all parts as a source of ingredients for medicines and cosmetics that promote health and well-being. This will provide theoretical support for the integrated use of such natural products.

Eco-friendly simultaneous extraction of pectins and phenolics from passion fruit (Passiflora edulis Sims) peel: Process optimization, physicochemical properties, and antioxidant activity

The objective of this study was to simultaneously extract passion fruit (Passiflora edulis) peel pectins and phenolics using deep eutectic solvents, to evaluate their physicochemical properties and antioxidant activity. By taking L-proline: citric acid (Pro-CA) as the optimal solvent, the effect of extraction parameters on the yields of extracted passion fruit peel pectins (PFPP) and total phenolic content (TPC) was. and the highest TPC (9.68 mg GAE/g DW) were attained under 90 °C, extraction solvent pH = 2, extraction time of 120 min and L/S ratio of 20 mL/g. In addition, Pro-CA-extracted pectins (Pro-CA-PFPP) and HCl-extracted pectins (HCl-PFPP) were subjected to high performance gel permeation chromatography (HPGPC), Fourier transform infrared spectroscopy (FT-IR), thermogram analysis (TG/DTG) and rheological measurements. Results verified that the Mw and thermal stability of Pro-CA-PFPP were higher than those of HCl-PFPP. The PFPP solutions featured a non-Newtonian behavior, and compared with commercially pectin solution, PFPP solution exhibited a stronger antioxidant activity. Additionally, passion fruit peel extract (PFPE) exhibited stronger antioxidant effects than PFPP. The results of ultra-performance liquid chromatography hybrid triple quadrupole-linear ion trap mass spectrometry (UPLC-Qtrap-MS) and high performance liquid chromatography (HPLC) analysis showed that (-)-epigallocatechin, gallic acid, epicatechin, kaempferol-3-O-rutin and myricetin were the main phenolic compounds in PFPE and PFPP. Our results suggest that Pro-CA can be considered as an eco-friendly solvent for high-efficient extraction of high-value compounds from agricultural by-products.

Nondestructive 3D phenotyping method of passion fruit based on X-ray micro-computed tomography and deep learning

Passion fruit is a tropical liana of the Passiflora family that is commonly planted throughout the world due to its abundance of nutrients and industrial value. Researchers are committed to exploring the relationship between phenotype and genotype to promote the improvement of passion fruit varieties. However, the traditional manual phenotyping methods have shortcomings in accuracy, objectivity, and measurement efficiency when obtaining large quantities of personal data on passion fruit, especially internal organization data. This study selected samples of passion fruit from three widely grown cultivars, which differed significantly in fruit shape, size, and other morphological traits. A Micro-CT system was developed to perform fully automated nondestructive imaging of the samples to obtain 3D models of passion fruit. A designed label generation method and segmentation method based on U-Net model were used to distinguish different tissues in the samples. Finally, fourteen traits, including fruit volume, surface area, length and width, sarcocarp volume, pericarp thickness, and traits of fruit type, were automatically calculated. The experimental results show that the segmentation accuracy of the deep learning model reaches more than 0.95. Compared with the manual measurements, the mean absolute percentage error of the fruit width and length measurements by the Micro-CT system was 1.94% and 2.89%, respectively, and the squares of the correlation coefficients were 0.96 and 0.93. It shows that the measurement accuracy of external traits of passion fruit is comparable to manual operations, and the measurement of internal traits is more reliable because of the nondestructive characteristics of our method. According to the statistical data of the whole samples, the Pearson analysis method was used, and the results indicated specific correlations among fourteen phenotypic traits of passion fruit. At the same time, the results of the principal component analysis illustrated that the comprehensive quality of passion fruit could be scored using this method, which will help to screen for high-quality passion fruit samples with large sizes and high sarcocarp content. The results of this study will firstly provide a nondestructive method for more accurate and efficient automatic acquisition of comprehensive phenotypic traits of passion fruit and have the potential to be extended to more fruit crops. The preliminary study of the correlation between the characteristics of passion fruit can also provide a particular reference value for molecular breeding and comprehensive quality evaluation.

Minor tropical fruits as a potential source of bioactive and functional foods

Tropical fruits are defined as fruits that are grown in hot and humid regions within the Tropic of Cancer and Tropic of Capricorn, covering most of the tropical and subtropical areas of Asia, Africa, Central America, South America, the Caribbean and Oceania. Depending on the cultivation area covered, economic value and popularity these tropical fruits are divided into major and minor tropical fruits. There is an annual increment of 3.8% in terms of commercialization of the tropical fruits. In total 26 minor tropical fruits (Kiwifruit, Lutqua, Carambola, Tree Tomato, Elephant apple, Rambutan, Bay berry, Mangosteen, Bhawa, Loquat, Silver berry, Durian, Persimon, Longan, Passion fruit, Water apple, Pulasan, Indian gooseberry, Guava, Lychee, Annona, Pitaya, Sapodilla, Pepino, Jaboticaba, Jackfruit) have been covered in this work. The nutritional composition, phytochemical composition, health benefits, traditional use of these minor tropical fruits and their role in food fortification have been portrayed.