Effect of preservation method on amino acid content in selected species
of edible mushroom
Department of Raw Material and Processing of Fruit and Vegetables, Agricultural University of Krakow, 122 Balicka Street, 30-149 Krakow, Poland
Received 10 November 2011
Received in revised form
5 March 2012
Accepted 22 March 2012
The present work determined the effect of the method of preservation (freezing or canning) on amino
acid content in Agaricus bisporus, Boletus edulis and Pleurotus ostreatus mushrooms. Before being
preserved, mushrooms were blanched in a solution containing citric, lactic and
Expressing the results in 100 g fresh matter, mushroom species was a more signiﬁcant factor than
product type in determining differences in the levels of individual endogenous and exogenous amino
acids; however, when the results were converted to 100 g protein, both factors were signiﬁcant. In 100 g
fresh matter, B. edulis contained 2e80% and 3e268% more endogenous and exogenous amino acids than
A. bisporus and P. ostreatus respectively. The main differences between frozen and canned mushrooms
were in the levels of alanine, arginine, proline, cysteine, methionine and tyrosine. Converted to 100 g of
protein, signiﬁcant differences between the products mainly concerned levels of asparagine, arginine,
glycine, glutamine, leucine, lysine, phenylalanine and valine. Compared with FAO/WHO patterns, limiting
amino acids were found only in frozen (leucine) and canned (lysine) B. edulis. CS index values were
generally lower for frozen than for canned mushrooms.
Ó 2012 Elsevier Ltd. All rights reserved.
Edible mushrooms are consumed worldwide due to their
ﬂavour, nutritional value and distinctive texture. They are also
believed to have therapeutic properties in relation to cancer, heart
disease, viral infection, cholesterol levels and hypertension, which
are attributed to dietary ﬁbre, mainly chitin; polysaccharides
forming the cell walls; and beta-glucans: homo- and hetero-
glucans (Bobek & Galbavy, 1999; Manzi & Pizzoferrato, 2000).
Mushrooms also contain considerable amounts of nitrogen
compounds, including protein (Shah, Khalil, & Jabeen, 1997). The
level of protein compounds, which account for over half of total
nitrogen, is determined by the composition of the substrate, size of
the sporocarp, maturity when picked and species, and varies
between 19 and 47 g/100 g dry matter (Agrahar-Murugkar &
Subbulakshmi, 2005; Beluhan & Ranogajec, 2011). Amino acids
occurring in the greatest quantities are alanine, asparagine, glycine
and glutamine (Akindahunsi & Oyetayo, 2006; Guo, Lin, & Lin,
2007; Manzi, Gambelli, Marconi, Vivanti, & Pizzoferrato, 1999;
Mdachi, Nkunya, Nyigo, & Urasa, 2004). The literature contains
divergent views on protein quality in mushrooms. The most
frequently cited limiting amino acids for both Agaricus bisporus,
Pleurotus ostreatus and Pleurotus tuber-regium are methionine and
cysteine, and additionally valine in the case of A. bisporus
(Akindahunsi & Oyetayo, 2006; Dabbour & Takruri, 2002; Shah
et al., 1997).
Mushrooms are extremely perishable. The method of preser-
vation applied is determined by such factors as the end use of the
product and the envisaged storage time. Freezing, drying and
canning are used for long-term preservation. The dominant trend
in modern food processing technology is towards convenience
foods of the “ready-to-cook” type, which can be consumed after
thermal treatment, as well as “ready-to-heat” and “ready-to-eat”
type foods (Sloan, 2005). These are characteristics of both frozen
and canned mushrooms.
The aim of this work wasto determine the effect of the method of
preservation on amino acid levels in A. bisporus (Lange) Sing., Boletus
edulis (Bull: Fr.) and P. ostreatus (Jacq.: Fr.) Kumm. mushrooms.
2. Materials and methods
2.1. Sample preparation
2.1.1. Preliminary treatment
The experimental material was frozen and canned A. bisporus
(Lange) Sing., B. edulis (Bull: Fr.) and P. ostreatus (Jacq.: Fr.) Kumm.
mushrooms after 12 months of storage. Fresh A. bisporus and
Corresponding author. Tel./fax: þ48 126624757.
E-mail address: email@example.com (E. Berna
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LWT - Food Science and Technology
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0023-6438/$ e see front matter Ó 2012 Elsevier Ltd. All rights reserved.
LWT - Food Science and Technology 48 (2012) 242e247