Pea vs soy protein for a Sri Lankan plant-based patty spec

By the Silk Foods Ceylon Editorial Team

The Ministry of Agriculture’s crop production plan for 2026 targets 5,990 hectares of soya bean across the two seasons, and sets aside 1,232,240 kg of certified soya seed for the Yala season alone. Field pea does not appear in the plan at any acreage. That asymmetry, rather than anything printed on either sack, is the first thing worth looking at when a local brand owner specifies the protein base for a plant-based patty.

The question usually arrives late, after the brand name, the pack design and the retail price have all been decided. It should arrive first. The base sets the protein claim, most of the raw-material cost, the label, the number of research rounds needed to kill off-notes, and how the patty behaves when it thaws in a chiller cabinet.

The number that settles most of the argument: DIAAS 98 against 73

Protein quality is measured by the digestible indispensable amino acid score, which reads the digestible content of each indispensable amino acid against a reference pattern and reports the lowest one. Measured in pigs against the pattern for people over three years old, soy protein isolate returns 98 and pea protein concentrate returns 73, with sulfur amino acids first limiting in both.

Those two numbers sit on opposite sides of a threshold that matters commercially. A score at or above 100 supports an excellent-quality description, and a score from 75 to 99 supports a good-source description. Pea protein concentrate at 73 clears neither.

Protein source	DIAAS, over 3 years	PDCAAS-like value	First-limiting amino acid	Where that lands
Soya flour	105	109	Sulfur amino acids	Above the excellent-quality threshold of 100
Soy protein isolate	98	102	Sulfur amino acids	Inside the good-source band of 75 to 99
Pea protein concentrate	73	84	Sulfur amino acids	Below the good-source band on the digestible measure
Whole-grain wheat	54	51	Lysine	Shown for reference, since a patty usually carries a cereal binder

Two honest caveats belong with that table. The pea figure is a concentrate, not an isolate, and an isolate concentrates the protein and lifts the score. And a patty is a blend, not a single powder, so the score that matters is the one for the finished formulation.

The blend argument cuts in pea’s favour more than the headline suggests. Wheat is limited by lysine, which legumes carry in quantity, while pea is limited by sulfur amino acids, which cereals carry. A pea-and-cereal patty scores better than either component alone. What it does not do is close the gap to a soy formulation on its own, because soy starts higher and shares the same limiting amino acid.

For the wider set of frozen plant-based formats and how they differ before this question even arises, the frozen vegan sausage and mince formats and the frozen seitan formulation work cover ground a patty brief usually touches.

What does each base actually cost on a first run?

On the same commercial pricing index for the second quarter of 2026, soy protein isolate averaged about USD 2,077 per tonne on a free-on-board basis out of China, and pea protein isolate about USD 4,000 per tonne free on board out of Indonesia. That is a ratio of roughly 1.9 to 1 before a single container moves.

Run it against a real first batch rather than a tonne. Take the lower end of a patty first run, 10,000 units at 80 g, which is 800 kg of finished product, and assume the protein base is 15 per cent of the wet formula. That is 120 kg of powder.

Line	Soy protein isolate	Pea protein isolate
Quoted price, second quarter 2026, free on board	USD 2,077 per tonne	USD 4,000 per tonne
120 kg for a 10,000-unit run at 80 g	USD 249	USD 480
Same figure at about LKR 332 to the dollar	LKR 82,700	LKR 159,400
Difference on the run		LKR 76,600 more
Difference per patty		LKR 7.66 more
Difference on one full day at 15,000 patties		about LKR 115,000 more

Read the per-patty line before the per-run line. LKR 7.66 on a single patty is small enough that a brand with a genuine reason to specify pea should specify pea and stop worrying about it. The run-level and day-level numbers are the ones that decide whether the reason is genuine, because they are what a year of production looks like.

Three things are missing from that table and all three widen the gap rather than closing it. Freight and insurance to Colombo. Duty and value added tax at the border. And the exchange rate on the day the letter of credit opens, which is a live exposure on a fully imported input in a way it is not on a raw material with a domestic crop behind it.

One more line belongs in the same calculation. Isolate is not the only form on offer: texturated soy protein and pea texturate both sit well below isolate pricing, and most patty formulations use a texturate for structure with a smaller isolate or binder addition for bind. Specifying isolate to isolate is the only like-for-like published comparison available, so the table uses it, but a real costing should be run on the exact grades quoted.

Soy has a crop behind it in Sri Lanka. Pea has none.

The 2026 crop production plan puts soya bean at 350 hectares for a planned 665 tonnes in the Maha season and 5,640 hectares for 11,580 tonnes in Yala, with 1,232,240 kg of certified seed released for the Yala crop. Every other field crop in the plan, from cowpea to black gram to sesame, appears with its own acreage. Field pea appears nowhere.

The practical consequence is narrower than it first looks, and worth stating plainly rather than overselling. Food-grade soy protein isolate used in Sri Lanka is imported too. The domestic crop matters at the other end of the chain: full-fat soy flour, defatted soy grits and locally texturated soy protein can be sourced inside the country on a domestic lead time, which is a real option for a patty formulation and no option at all on the pea side.

So the honest framing is not that soy is local and pea is imported. It is that soy gives a formulator a domestic fallback when a shipment slips, and pea does not. On a product with a 5,000 to 10,000-unit first run and a retail listing date attached to it, a fallback is worth more than most brand owners price it at.

Which base survives the label?

Until recently this was the clearest argument for pea. The Codex general standard for the labelling of prepackaged foods listed peanuts and soybeans among the foods that shall always be declared, which put soy in the same sentence as milk, eggs and fish for any brand reading the international rulebook.

That changed in December 2024. Following the forty-seventh session of the Codex Alimentarius Commission the standard was revised on allergen labelling: sesame was added as internationally relevant, and soy was retrograded to regionally relevant only, leaving cereals containing gluten, crustaceans, eggs, fish, peanuts, milk, sesame and named tree nuts on the mandatory list.

For a Sri Lankan retail SKU, that revision changes less than it sounds like it should. The Food (Labelling and Advertising) Regulations 2022, notified in the official gazette on 14 February 2023 and brought into force from 1 July 2025 after a series of extensions, require the common name of the product in bold in all three languages, a complete list of ingredients by common name in descending order of weight at the time of manufacture, and nutrition labelling in letters no smaller than 1.5 mm. Soy appears on the pack either way, because the ingredient list names it.

Where the Codex position does bite is on export ambition, and that is a question to settle before the first sample rather than after the first order. The European Union, the United Kingdom and the United States all keep soy on their own mandatory allergen lists, and a regional Codex classification does not move a national rule. A brand building towards a diaspora or specialty shelf abroad is choosing between an allergen box on the pack and a higher raw-material cost, and the sequence of those two decisions is what usually goes wrong.

The research team at the Matale facility sees the same conversation repeat on first patty briefs. A founder arrives with a soy formulation, a price expectation built on a soy costing, and a plan to be on a shelf abroad within eighteen months. The formulation work is not the problem in that brief. The problem is that switching the base after artwork and nutrition panels are locked means a new sample cycle, a new nutrition analysis, a new panel and a re-costing, and the two to four sample iterations that would have been routine at the start become a re-launch instead.

The regulatory calendar that sits underneath all of this is worked through in the step-by-step packaged-food submission to the Sri Lanka Standards Institution.

What each base does on the forming line

Protein quality and price are decided on paper. Texture is decided on the line, and it is where a brief that looked settled tends to reopen.

Soy texturate has been made at industrial scale for decades, which shows up as predictability: consistent hydration behaviour, a fibrous bite that survives forming and freezing, and a flavour profile that is neutral enough for most seasoning systems to sit on top of. Pea brings a distinct earthy and slightly bitter note that has to be masked rather than ignored, and masking is a formulation cost paid in sample rounds. It also tends to need more attention on binding, which usually means a starch or hydrocolloid adjustment before the patty holds its shape through forming, freezing and reheating.

None of that makes pea a worse base. It makes pea a base that arrives at a locked recipe one or two iterations later than soy does, which matters when a listing date is fixed and the iteration budget is not.

Buyer's checklist: settle these before briefing a protein base The protein claim you intend to print, and whether the finished patty can carry it on the base you have chosen rather than on the base you like. Target protein per 100 g of finished patty, not per 100 g of the powder. The two numbers are far apart once water, fat, binder and breading are in. The inclusion rate you are assuming, written as a percentage of the wet formula, so the costing can be checked rather than argued about. Whether isolate, concentrate or texturate is being specified. These are three different raw materials at three different prices and three different textures. A landed-cost line, not a quoted price. Freight, duty, value added tax and the exchange rate on the day the letter of credit opens all sit between the two. The export ambition, stated now. Soy carries a mandatory allergen declaration in the European Union, the United Kingdom and the United States regardless of what Codex says. A masking budget for off-notes, in sample rounds rather than in rupees. Pea in particular usually costs an extra iteration or two. The freeze-thaw and reheat conditions the patty will actually meet in the channel it is sold into, since binding behaviour separates the two bases more than protein content does.

The mechanics of the run itself, from forming through blast freezing, are set out in the 5,000 to 10,000-unit first patty run, and the sourcing side in the vegan burger patty line with local sourcing. A nugget SKU on the same line follows the frozen nugget spec.

So which one gets specified first?

Set the two side by side on the dimensions a brief actually turns on, and the answer stops being a matter of preference.

Dimension	Soy	Pea	Which wins
Protein quality on the digestible measure	Isolate at 98, flour at 105	Concentrate at 73	Soy
Raw-material price on the same index	About USD 2,077 per tonne	About USD 4,000 per tonne	Soy
Domestic raw-material fallback	Local crop, local texturate and flour available	None at any acreage	Soy
Allergen status on a Sri Lankan pack	Named in the ingredient list	Named in the ingredient list	Neither
Allergen status on a European, British or American pack	Mandatory allergen declaration	No allergen declaration required	Pea
Flavour work needed	Neutral enough for most seasoning systems	Earthy note needs masking	Soy
Binding and freeze-thaw behaviour	Predictable at scale	Usually needs a binder adjustment	Soy
Positioning value on a soy-free proposition	Not available	The whole point of choosing it	Pea

The decision rule that falls out of that table is short. Specify soy first unless one of three things is true: the brand is selling an explicitly soy-free or allergen-conscious proposition, the SKU is aimed at a market where a soy allergen declaration undermines the positioning, or a named channel has asked for pea by name. Any of those three makes pea the right base and the extra LKR 7.66 a patty the price of the position. None of them, and pea is a preference being paid for at roughly double the raw-material rate.

There is a fourth path that suits a brand genuinely torn between the two, and it is usually the cheapest. Launch on soy, prove the SKU sells, and bring pea in as a second variant once the line, the artwork and the retail relationship are all established. The formulation work is not wasted, because the seasoning system and the process parameters carry across.

The iteration budget behind either path is set out in the research and development iteration budget for a Sri Lankan launch.

Frequently asked questions

Is pea protein better than soy protein for a burger patty?

Not on protein quality or price. Soy protein isolate scores a DIAAS of 98 against 73 for pea protein concentrate, and soy isolate was quoted at roughly half the price of pea isolate in the second quarter of 2026. Pea wins on allergen labelling in export markets and on a soy-free positioning.

Does a soy-based patty need an allergen warning in Sri Lanka?

Soy is named on the pack regardless, because the Food (Labelling and Advertising) Regulations 2022 require a complete ingredient list by common name in descending order of weight. Codex moved soy to a regionally relevant classification in December 2024, but the European Union, the United Kingdom and the United States all still require a soy allergen declaration.

How much more does pea protein cost than soy protein?

Roughly 1.9 times on published second-quarter 2026 free-on-board quotes, at about USD 4,000 per tonne for pea protein isolate against USD 2,077 for soy protein isolate. On a 10,000-unit patty run at 80 g and 15 per cent inclusion, that is a difference of about LKR 76,600, or LKR 7.66 a patty, before freight and duty.

Can Silk Foods Ceylon develop a plant-based patty on either protein base?

Yes. Research and new product development, listed as Co-Development on the Silk Foods Ceylon brochure, covers two to four sample iterations per variant before a recipe locks, on either base. The Matale line runs 15,000 patties per day with a first-run minimum of 5,000 to 10,000 units per SKU.

How Silk Foods Ceylon can help

For local FMCG brands moving a plant-based patty from a kitchen recipe to a retail SKU, Silk Foods Ceylon (SFC) runs contract manufacturing and product development from a 10,000 sq ft cellular-manufacturing facility in Matale. The patty line runs 15,000 units per day through forming, battering, breading, frying and blast freezing, with a first-run minimum of 5,000 to 10,000 units per SKU, and the in-house research team works through two to four sample iterations per variant before a recipe locks. Specifying the protein base at that stage, rather than after artwork and nutrition panels are committed, is what keeps a base change from turning into a re-launch. The facility is BRCGS- and FSSC 22000 V6-audited, with SLSI clearance and Sri Lanka Food Act labelling support inside a standard engagement.

To brief a patty project, email b2b@esilkroute.com.lk or call +94 76 441 0389 / +94 76 918 5744.

Sources

J. K. Mathai, Y. Liu and H. H. Stein, Values for digestible indispensable amino acid scores (DIAAS) for some dairy and plant proteins may better describe protein quality than values calculated using the concept for protein digestibility-corrected amino acid scores (PDCAAS), British Journal of Nutrition, 2017, volume 117, pages 490 to 499, Table 7, giving DIAAS values for children over three years, adolescents and adults of 98 for soya protein isolate, 105 for soya flour, 73 for pea protein concentrate and 54 for wheat, with sulfur amino acids first limiting in the three legume and soya entries. doi.org (retrieved 31 August 2026).

Codex Alimentarius, General standard for the labelling of prepackaged foods, CXS 1-1985, adopted 1985 and amended through 2010, clause 4.2.1.4 listing the foods and ingredients known to cause hypersensitivity that shall always be declared, including peanuts, soybeans and products of these. fao.org (retrieved 31 August 2026).

Keller and Heckman, Tomorrow’s Food and Feed, Codex Alimentarius: main outcome of the 48th Committee on Food Labelling, 16 December 2024, reporting that in the revised allergen provisions sesame is treated as internationally relevant and soy is retrograded as regionally relevant only. khlaw.com (retrieved 31 August 2026).

United States Department of Agriculture, Foreign Agricultural Service, GAIN report CE2025-0003, Sri Lanka extends implementation of the Food Labeling and Advertising Regulations-2022 by additional six months, 26 February 2025, prepared by Thilani Kankanamge, recording the move of the implementation date from 1 January 2025 to 1 July 2025 and the gazette notification of 28 December 2024. fas.usda.gov (retrieved 31 August 2026).

United States Department of Agriculture, Foreign Agricultural Service, GAIN report CE2023-0011, Sri Lanka enacts new legislation for food labeling and advertising, 23 August 2023, setting out the Food (Labeling and Advertising) Regulations 2022 requirements: the common name in bold type in all three languages, a complete list of ingredients by common name in descending order of weight at the time of manufacture, nutrition labelling in letters not less than 1.5 mm, and the exemption below 25 g or 30 ml. fas.usda.gov (retrieved 31 August 2026).

Ministry of Agriculture, Sri Lanka, crop production plan data for 2026, published January 2026, giving national soya bean targets of 350 hectares for 665 tonnes in Maha 2025/26 and 5,640 hectares for 11,580 tonnes in Yala 2026, with 1,232,240 kg of certified soya bean seed available for Yala 2026, and listing no field pea crop. agrimin.gov.lk (retrieved 31 August 2026).

ChemAnalyst pricing data, second quarter 2026, quoting soy protein isolate in the Asia-Pacific region at an average of about USD 2,077 per tonne free on board China and pea protein isolate at about USD 4,000 per tonne free on board Indonesia. chemanalyst.com (retrieved 31 August 2026).

Central Bank of Sri Lanka daily exchange rates, with the rupee quoted around LKR 332 to the United States dollar in late August 2026, used for the rupee conversions in this article. cbsl.gov.lk (retrieved 31 August 2026).