Acidity Drop and Coloration in Clementine: Implications for Fruit Quality and Harvesting Practices

p-Synephrine Indicates Internal Maturity of Citrus grandis (L.) Osbeck cv. Mato Peiyu-Reclaiming Functional Constituents from Nonedible Parts

The processing of Citrus grandis Osbeck cv. Mato Peiyu (CGMP) fruits generates a considerable amount of waste, mainly the flavedo, albedo, and segment membrane; the generated waste yields severe environmental and economic challenges. In this study, we tried to reclaim some functional chemicals from the waste. Our data indicated that the essential oil content in the flavedo was 0.76-1.34%, with the major component being monoterpenes (93.75% in August, declining to 85.56% in November, including mainly limonene (87.08% to 81.12%) and others such as β-myrcene). p-Synephrine (mg/100 g dry weight) declined accordingly (flavedo, 10.40 to 2.00; albedo, 1.80 to 0.25; segment membrane, 0.3 in August, 0.2 in September, and none since October). Polyphenols (in μg/g) included gallic acid (70.32-110.25, 99.27-252.89, and 105.78-187.36, respectively); protocatechuic acid (65.32-204.94, 26.35-72.35, and 214.98-302.65, respectively), p-coumaric acid (30.63-169.13, 4.32-17.00, and 6.68-34.32, respectively), ferulic acid (12.36-39.36, 1.21-10.25, and 17.07-39.63, respectively), and chlorogenic acid (59.19-199.36, 33.08-108.57, and 65.32-150.14, respectively). Flavonoids (in μg/g) included naringin (flavedo, 89.32-283.19), quercetin (181.05-248.51), nobiletin (259.75-563.7), hesperidin, and diosmin. The phytosterol content (mg/100 g) was 12.50-44.00 in the flavedo. The total dietary fiber in the segment membrane was 57 g/100 g. The antioxidant activity against the DPPH^• and ABTS^+• free radicals was moderately high. In conclusion, the waste of CGMP fruits is worth reclaiming for essential oil, p-synephrine, polyphenolics, and dietary fiber. Notably, p-synephrine content (flavedo: <8 mg/100 g dry weight, albedo: <2.0, or segment membrane: <0.4 mg) can serve as a marker of the internal maturation of CGMP fruits.

Product Qualification as a Means of Identifying Sustainability Pathways for Place-Based Agri-Food Systems: The Case of the GI Corsican Grapefruit (France)

Existing frameworks offer a holistic way to evaluate a food system based on sustainability indicators but can fall short of offering clear direction. To analyze the sustainability of a geographical indication (GI) system, we adopt a product-centered approach that begins with understanding the product qualification along the value-chain. We use the case of the GI Corsican grapefruit focusing on understanding the quality criteria priorities from the orchard to the store. Our results show that certain compromises written into the Code of Practices threaten the system’s sustainability. Today the GI allows the fruit to be harvested before achieving peak maturity and expectations on visual quality lead to high levels of food waste. Its primary function is to help penetrate mainstream export markets and to optimize labor and infrastructure. Analyzing the stakeholders’ choices of qualification brings to light potential seeds for change in the short run such as later springtime harvests, diversification of the marketing channels, and more leniency on the fruit’s aesthetics. These solutions lead us to reflect on long-term pathways to sustainable development such as reinforcing the fruit’s typicality, reducing food waste, reorganizing human resources, and embedding the fruit into its territory and the local culture.