Spice Report: 2024 Rattan Pepper New Crop Assessment

In June 2024, the Rushi spice survey team conducted an in-depth assessment of the Rattan Pepper (藤椒) harvesting base, examining aspects such as planting, initial processing, and storage. The goal was to evaluate the food safety level of Rattan Pepper raw materials.

Overview of Rattan Pepper

Rattan Pepper, named for its vine-like branches, belongs to the Rutaceae family, specifically the Zanthoxylum armatum DC. It is widely distributed across the Sichuan Basin and the surrounding hilly regions, including Sichuan Province, most of Chongqing, and Guizhou Province. In modern cultivation, the vine-like appearance of Rattan Pepper trees has become less pronounced.

Plant Morphology

• Type: Small shrub

• Branches: Gray-brown with small thorns

• Leaves: Oval or lanceolate with fine serrated edges and glandular points between teeth; green on the surface and grayish-green on the underside with sparse oil dots.

• Fruits: Follicle fruit that splits naturally when mature, releasing seeds. The pericarp is green to emerald green, densely covered with oil cells containing a transparent oily substance, which is Rattan Pepper's essential oil.

 Sensory Description

The unique aroma of Rattan Pepper primarily derives from terpenes, alcohols, aldehydes, ketones, esters, and olefins. The numbing sensation is mainly due to hydroxy-α-sanshool, hydroxy-β-sanshool, and hydroxy-γ-sanshool, with Rattan Pepper containing less of these compounds compared to Red Sichuan Pepper, making it more palatable for those who do not typically enjoy the numbing taste. 

Planting Conditions

• Main Production Areas: Sichuan Province, most of Chongqing, and Guizhou Province.

• Altitude: 300-800 meters

• Terrain: Plains, hills, and mountains

• Soil: Most soils are suitable, provided they have good irrigation and drainage.

• Climate: Subtropical humid climate, prefers moisture and nutrients but is not tolerant of waterlogging.

Cultivation Methods

• Seed Propagation: Mature Rattan Pepper seeds are sown in autumn and transplanted the following year.

• Grafted Seedlings: High-quality scions are grafted onto rootstocks for early and high yields, though at a higher cost.

• Transplanting: Seedlings with robust growth and dense root systems are transplanted to the fields.

• Planting Density: 2-3.5 meters between plants, 3-4 meters between rows.

 Fertilization and Irrigation

• Fertilization Cycle: 3-4 times per year

• Types of Fertilizer: Compound fertilizers and organic fertilizers

• Application Methods: Broadcast or trench application

• Fertilizer Amount: Approximately 1-1.5 kg per plant per year, with 7.5 kg of organic fertilizer per plant per year

• Irrigation: Mostly reliant on natural rainfall, with some areas equipped with irrigation systems

Pest and Disease Control

• Methods: Mainly chemical control, supplemented by green control measures such as insecticidal lamps, yellow sticky traps, and biological pesticides.

• Common Pesticides:

• Insecticides: Imidacloprid, acetamiprid, lambda-cyhalothrin, propargite, etoxazole

• Fungicides: Tebuconazole, mancozeb, propineb, prochloraz, pyraclostrobin

• Application Methods: Spraying with sprayers, drones, or high-pressure spraying systems

Harvesting

• Harvest Time: Early June to mid-July

• Method:

1. Harvest branches with 3-5 cm of stem remaining.

2. Cut harvested branches into 40-60 cm segments and place them in plastic crates.

3. Transport to drying facilities for drying.

• Conditions: Avoid harvesting in rainy weather

Processing and Storage

Processing Steps

1. Loading: Rattan Pepper branches are evenly loaded onto conveyor belts in drying boxes. Loading quality affects drying quality.

2. Withering: Only the fan is operated without heating. Depending on the material's moisture content, withering takes 4-8 hours before gradually increasing the temperature.

3. Gradual Heating: The drying temperature gradually increases over time, typically not exceeding 48°C, with a drying time of 36-48 hours.

4. Unloading: After drying, the material is promptly unloaded for separation of fruit, branches, leaves, and seeds, usually done manually or by conveyor belts.

5. Initial Screening:

• Threshing: A threshing machine separates the pericarp from branches, leaves, and seeds.

• Screening: Equipment like air classifiers and comprehensive screens remove seeds, thorns, leaves, and stems.

1. Storage: Stored in cold storage at 0-5°C, ensuring ventilation and protection from pests, rodents, and moisture.

2. Packaging: Packed in woven bags with inner linings.

3. Trade: Large growers sell directly to buyers; small growers sell through large growers or at trading markets.

 Comprehensive Food Safety Assessment

Based on the National Food Safety Risk Assessment Center's guidelines and actual agricultural product conditions, Rushi conducted a food safety risk analysis for Rattan Pepper raw materials.

Traceability Risk

• Base Rattan Pepper: Can be traced to individual growers.

• Farmers' Rattan Pepper: Sourced from numerous small farms, posing traceability challenges.

Pesticide Residue Risk

• Base Rattan Pepper: Scientific pesticide use with usage records.

• Farmers' Rattan Pepper: Higher risk due to potential overuse of pesticides to increase yield. Long-term monitoring has shown pesticide residue exceedances in some areas, such as Jiangjin.

Initial Processing Risk

• Base Energy Sources: Use of clean energy such as electricity, natural gas, and methanol.

• Farmers and Middlemen: Some use coal, leading to contamination with substances like snail shells, hair, stones, and coal ash. Contaminants like benzo[a]pyrene and sulfur dioxide can form from prolonged high temperatures and coal combustion.

Storage Risk

• Base Rattan Pepper: Stored in woven bags with inner linings at low temperatures.

• Farmers' Rattan Pepper: Often stored in plastic or woven bags at room temperature, with risks including non-food-grade plasticizers and loss of volatile compounds.

 Rushi's Measures to Mitigate Risks

1. Pre-Harvest Research:

• Early in the harvest season, Rushi organizes field research, sampling, and testing to evaluate quality and food safety, with records maintained.

2. Base Cooperation:

• Establish strategic partnerships with Rattan Pepper planting bases, providing guidance and monitoring from seedling to drying.

• Promote advanced agricultural practices, urging the use of low-toxicity pesticides and organic fertilizers, and supporting the installation of green pest control measures like insecticidal lamps and sticky traps.

3. Raw Material Sampling and Testing:

• Each batch of raw materials is sampled according to the "GB/T 12729.2-2020 Spices and Condiments - Sampling Methods" for internal or external testing. Non-compliant materials are rejected.

4. Storage:

• Classification: Raw materials are stored separately to avoid cross-contamination.

• Low-Temperature Storage: Stored in large cold storage at -10 to 0°C to reduce oxidation and maintain quality.

5. Regular Quality Inspections:

• Conduct regular sensory and physicochemical tests (volatile oils, numbing compounds) to monitor quality changes.

Comprehensive Assessment

The comprehensive risk control measures implemented at the base level result in a safe food safety rating for base Rattan Pepper. However, Rattan Pepper from numerous small farms poses relatively higher risks due to complex sources and control challenges.

Overall, the 2023-2024 growing season experienced normal climatic conditions, with Rattan Pepper showing good growth and high yields across various planting bases. Despite market oversupply leading some bases to abandon management, overall production increased by approximately 50% compared to 2023, according to Rushi's survey data (for reference only).