Harvesting
The duration of the culture period was typically 45 days for best growth rate, quality of carrageenan. The seaweed be removed from the lines and clean all impurities such as plastic straw, algae, sand, and shells, fishes which are not acceptable to buyers or processors. In average the weight of seaweed can increased 5 times per cycle of 45 days at the yield of 2.5kg/meter of cultivation line. Seaweed is harvested manually and transport to land by boat or net. Mechanical harvest is not widely available yet. The harvesting parameters is presented in Table 1 and Figure 1.
Table 1. Harvesting parameters and information|
Parameters |
Description |
|
Number of harvests per
year |
7 (3-10) times depend on
the regions |
|
Types of harvest (full/partial) |
Full |
|
Time of harvest from
plantation (days) |
45 days (30 - 60 days) |
|
Average yield per
harvest (wet wt. per m per harvest) |
2.5 (2-5) kg/meter/harvest
|
|
Average weight increase per
cycle (45 days) |
5 (3-8) times |
|
Harvesting method |
Manual |
|
Transport of harvest to
land |
Boat, float or nets at
low tide |
Adapted from
Post-harvest Handling, Drying and Packing
Postharvest handling is very important as it affects the quality of the seaweed and thus the quantity and quality of carrageenan. Dried seaweed can be divided into four basic categories, which are: (1) conventional (e.g. platform, hanging, indoor (shade) and ‘sauna’); (2) passive (e.g. greenhouse concept, chimney concept drier); (3) active (e.g. freeze drier, de-humidifier and oven); and (4) hybrid (e.g. wind turbine drier, double-pass solar collector with fins). Since the successful cultivation of Eucheumatoids began in the early 1970s, low technology and cheaper conventional methods of drying harvested seaweed have remained popular with the majority of farmers. New drying methods are still in the early stages of development and technology transfer to the industry (Ali, et al., 2017). The post-harvesting information, summary of advantages and disadvantages of varied drying systems is presented in Table 2 and Table 3.
Table 2. Post-harvesting
information
|
Parameters |
Description |
|
Cleaning and drying |
|
|
Cleaning |
Check the
seaweed and clean by hand, pressure washer if needed |
|
Drying method |
Sun drying by
platform or hanging line up |
|
Duration of drying (in good weather) |
2-4 days |
|
Wet-to-dry ratio |
7:1 |
|
Moisture content after drying |
35% - 50% |
|
Treatment of cultivation lines |
Sun or shade
drying, rubbing, beating |
|
Marketing and quality parameter of dried seaweed |
|
|
Point of Sales (POS) |
Drying platforms,
famer's house or collective warehouse |
|
Primary buyer |
Local collector
or trader |
|
Type of transaction |
Cash |
|
Type of quality test at POS |
Just visual /
touch, most of the times based on trust |
|
Other quality parameters |
Max. 3%
impurities and 1% sand |
|
Unit of sales |
50 - 100 kg per
nylon sack |
|
Certification |
None |
Adapted from
Eucheumatoids are sold in two forms: (1) dried seaweed used as a raw material in the processing of carrageenan and (2) fresh seaweed used as a seedling source. The value chain ends with the form of carrageenan being exported to the international market (Figure 2). The price of dried seaweed varies according to a combination of seaweed quality, and demand from the carrageenan industry. Example of seaweed carrageenan value chain and price in Malaysia 2018 (Figure 3. Example of seaweed carrageenan value chain and prices in Malaysia in 2018.
The carrageenan industry can be divided into three main sectors based on production technology. These regions are the SRC, GP and AP and the mixed region (Figure 4). The SRC and GP sectors are mainly located in Asia, which is basically linked to raw material supply. The AP and hybrid sector is located in the west, characterized by a relatively small number of companies serving high-value, niche markets, including toothpastes and pharmaceuticals and the diary market.
Figure 2. Overview of the seaweed carrageenan value chain and relationship between trader and farmer
Source:
Figure 3. Example of seaweed carrageenan
value chain and prices in Malaysia in 2018.
SRC Semi-refined carrageenan; GP Gel press; AP Alcohol precipitation
Source: (Campbell & Hotchkiss, 2017)
Figure 4. Schematic of the
carrageenan industry at present, showing major segmentation by seaweed
resource, production technology and key applications
Food Safety and Sustainable Seaweed
Value Chain Development
Carrageenan is safe to use as a food additive as well as for use in infant formula. However, there is controversy about the health food safety of carrageenan above certain consumption levels. Further research and action is needed to reduce the impact of the controversy (Neish & Suryanarayan, 2017) . Harmonized regional and national legislation on food safety hazards in seaweed are generally lacking. Although some private standards have been recently introduced (e.g., by the Aquaculture Stewardship Council/Marine Stewardship Council and the Norwegian Seaweed Farms), they either do not address food safety directly, or they do not do so in sufficient depth. There is, therefore, a significant regulatory gap concerning food safety in seaweed that requires attention (FAO & WHO, 2022).
The history of the value chain from seaweed to carrageenan has been reflected in changes in value chain linkages from 1974 to the present. Direct governance was typical during the early development of eucheumatoid seaweed farming from early 1970 until until the mid-1980s. Farmer linkages were directly to company representatives including trainers, extension workers and staff of company-operated buying stations. Direct governance value chains did not prove to be sustainable. They have evolved towards a “relational” mode in order to enhance sustainability as depicted in Figure 11.
The second phase of the value chain development occurred from the mid-1980s until the mid-1990s as modular governance substantially displaced direct governance. Processors still determined product specifications and trade rules but they operated through integrated suppliers.
The third phase of value chain development took place in the mid-1990s when market governance began to replace direct and modular governance. "Long-hand" trading between buyers and sellers became common when large volumes of seaweed were sold under short-term contracts or on the spot market. Market governance tends to be “current” and does not support mechanisms toward sustainability. Therefore, traceability and quality control, and stability of seaweed prices become more difficult.
Modified from
Figure 5. Governance models of
tropical (carrageenan) seaweed value chains
References
Ali, M. K. M. et al., 2017. Post-Harvest Handling of Eucheumatoid Seaweeds. In: A. Q. Hurtado, A. T. Critchley & I. C. Neish, eds. Tropical Seaweed Farming Trends, Problems and Opportunities Focus on Kappaphycus and Eucheuma of Commerce. Cham, Switzerland: Springer International Publishing AG, pp. 131 -1 45.
Neish, I. C. & Suryanarayan, S., 2017. Development of Eucheumatoid Seaweed Value-Chains Through Carrageenan and Beyond. In: A. Q. Hurtado, A. T. Critchley & I. C. Neish, eds. Tropical Seaweed Farming Trends, Problems and Opportunities. Cham, Switzerland: Springer, pp. 172-192.
Nor, A. M., Gray, T. S., Caldwell, G. S. & Stead, S. M., 2019. A value chain analysis of Malaysia’s seaweed industry. Journal of Applied Phycology, p. 11.
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