BMP testingFruit, vegetables and their residuessingle study (2 samples)

Mangosteen seeds — BMP: 2 studies, weighted mean 544 m³ CH₄/t VS

Mangosteen seeds are a fruit waste with a more compact, more fibrous structure than the pulp; the dataset examined fresh seeds and seeds from spoiled fruit.

CH₄ ≈ 52 % (estimate)

Published 19 August 2021Updated 29 October 20263 min readFeedstockData Editorial Team

Photo Basile Morin / Wikimedia Commons, licence CC BY-SA 4.0, source file; changes: cropping

Weighted mean: 544m³ CH₄/t VS
Range: 535–552m³ CH₄/t VS
Records: 2single study (2 samples)
Publications: 1source
Temperatures: 35 °Cof the test

Methane in biogas

≈51–54% CH₄

Medium methane content · ≈ 5.2 kWh/m³ of biogas

estimate from the substrate type The collected studies contain no measurement. The interval follows from the approximate composition (carbohydrate-dominated (no protein or fat characteristics)) and the yields of compound groups according to FNR.

How we calculate it and what the zones mean

Rating for biogas plants

not rated — editorial rating for biogas plants

Not rated: no dry matter or volatile solids in the data. We calculate the rating when the dry matter and volatile solids of the material are known.

Editorial rating per the methodology

Add to the co-digestion calculator CSV data

BMP curves from 2 studies

Weighted mean Individual records

Dashed lines are a model curve (first-order kinetics, B(t) = B₀·(1 − e^−kt)); the end point comes from the publication. All curves are model curves.

Cumulative methane production over the test [m³ CH₄/t VS]. The thick line is the weighted mean of all records (544); dots mark the end values given in the publications. Point at the chart to read values; click a legend item to hide or show a record.

Records and sources

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Source	BMP m³ CH₄/t VS	Temperature	Sample	Curve
Sanjaya et al. (2016) · 1 DOI	535	35 °C · mesophilic	Rooten mangosteen seed	end point (model curve)
Sanjaya et al. (2016) · 2 DOI	552	35 °C · mesophilic	Fresh ripe mangosteen seed	end point (model curve)
Weighted mean	544	arithmetic mean 544, SD 12

Typical composition

Dry matter (DM): 29.4% (range 24–34.9)

Median and range of the determinations reported in the publications behind this substrate's BMP records (read from: MY-D); dry matter: 2 determinations, volatile solids: 0 determinations.

Sources: Sanjaya et al. (2016).

The composition of the raw material varies between batches — for plant calculations use an analysis of your own sample. The calculator inserts typical values automatically.

Process properties

Low confidence: the description is based on general characteristics of the substrate group, not on studies of this material. Treat it as a hint to be verified.

No published process studies

The literature we use does not describe the advantages or drawbacks of digesting this substrate beyond the BMP test results. Below are process characteristics assigned on the basis of the type of material — an editorial classification, not a study result.

slowly degrading: slow degradation, requires a long retention time
fibrous: lignocellulose, long fibres → floating layer, harder mixing, slow degradation
seasonal: seasonal availability — requires storage
variable composition: high variability of composition between batches

Dosing

The sources do not give a safe share of this substrate in the feed.

Introduce gradually, starting with a small dose and monitoring the process (e.g. FOS/TAC, pH, gas composition).

Sources of the process data

The co-digestion calculator will assess a specific mixture containing this substrate.

What it is and where it comes from

Mangosteen (Garcinia mangostana) seeds are a waste arising during the processing of the fruit. Mangosteen is grown mainly in South-East Asia, and in Poland it occurs only as an imported fruit. The seeds are separated from the pulp and peel, so in processing they can form a separate stream, although usually of small mass.

Properties relevant to digestion

The seeds have a lower moisture content than the pulp, and their dry matter contains more fibre and substances that are harder for bacteria to access. The content of simple sugars is lower than in the pulp, so the risk of rapid acidification is smaller. The structure is compact, which slows hydrolysis if the seeds have not been comminuted. The typical inhibitors present in the peel are not found in them, but a precise assessment of the composition requires chemical analysis of the specific batch. Grinding is required, because whole seeds may react poorly and settle at the bottom of the digester.

How to read the spread of results

The dataset contains several records from a single study, describing fresh seeds and seeds from spoiled fruit. The results are close to one another, which suggests that the condition of the fruit mattered less for the seeds than for the pulp. A single study, however, does not establish a general rule. The result is affected by the degree of seed comminution, the variety, sample preparation (drying, freezing) and the inoculum.

In biogas plant practice

Mangosteen seeds are a material of local significance. In co-digestion they are introduced in a mixture with wastes of higher degradation rate, after shredding. Because of the compact structure, their share in the feed is usually limited. For installations in Poland they have no practical application, but the data help to assess similar seeds of tropical fruit.

In the balance of the whole waste stream from a processing plant, the seeds are usually a minority fraction, so their effect on digester operation depends on the proportion relative to the pulp and peel and on how well they are mixed in the batch.

If the seeds are used, it is worth checking that the batch is not contaminated with peel residues, which contain phenolic compounds and other secondary metabolites; their presence may change the behaviour of the material in the digester more than the seed content itself.

Methodology in brief

BMP is the amount of methane obtained from volatile solids (VS) in a batch test, given in m³ CH₄ per tonne of VS (numerically the same as NmL CH₄/g VS in the publications) and converted to normal conditions (0 °C, 101.325 kPa). The weighted mean gives each publication a total weight of 1, split equally between its results for the substrate — a paper testing twenty varieties does not outweigh a paper with a single sample. In inter-laboratory programmes the unit is the laboratory (total weight 1), and within it the weight of a test grows with the number of bottles (replicates). Results after pretreatment (e.g. thermal, chemical, enzymatic) are shown separately and are not included in the mean.

Solid lines are curves measured in the tests. Where a publication gives only the final result, we draw a first-order kinetic model, B(t) = B₀·(1 − e^−kt): only the end point comes from the publication, and the shape of the curve serves purely as visualisation — do not read the production on a particular day from it. For this substrate k = 0.245 d⁻¹ was assumed (median of rate constants k reported in the sources and/or fitted to the mean measured curves).

The statistics describe the spread of published results — a descriptive compilation, not a meta-analysis or a guarantee of plant yield.

Full methodology and correction policy

Bibliography

Sanjaya, A.P.; Cahyanto, M.N.; Millati, R. (2016). Mesophilic batch anaerobic digestion from fruit fragments. Renewable Energy 98, 135–141. DOI: 10.1016/j.renene.2016.02.059 DOI

All sources of the site: bibliography.