Effects of drying on the nutrient content and physico-chemical and sensory characteristics of the edible kelp Saccharina latissima
The effects of convective air-drying at 25, 40, and 70 °C and freeze-drying on the quality of the edible kelp Saccharina latissima to be used for food were investigated. Based on the analysis of the carbohydrate and amino acid profiles, as well as polyphenol, fucoxanthin, and ash contents, no significant differences were detected among sample groups, and air-drying up to 70 °C results in equally nutritious products at shorter processing times. Only the iodine content was found lower in freeze-dried compared to air-dried samples. The swelling capacity of the air-dried samples was significantly lower than in freeze-dried samples, particularly at high temperatures (40 and 70 °C), reflecting alteration of the physico-chemical properties of the seaweed during air-drying (attributed to product shrinkage) and reduced capacity of the final product to rehydrate. Structural differences between air-dried products at 25 and 70 °C may explain the differences in mouthfeel perception (dissolving rate) among the two sample groups observed during a sensory evaluation. Overall, the drying temperature within this range did not alter neither the aroma (i.e. odor) nor the flavor intensity of the product. In food applications where the product’s mechanical properties (e.g. porosity) are essential, freeze-drying, and to a lesser extent, air-drying at low temperatures, will result in higher quality products than air-drying at higher temperatures.
KeywordsAir-drying Freeze-drying Nutrients Physico-chemical properties Seaweed Sensory
The authors gratefully acknowledge Jorunn Skjermo and SINTEF Ocean’s seaweed cultivation team for providing the biomass, Veronica Hammer Hjellnes for the free amino acid characterization of the samples, Turid Fylling Standal for the analysis of the samples physico-chemical properties (WBC, OBC, SC), and panel members from Møreforsking Ålesund AS, who participated to the sensory evaluation of the samples.
This work was conducted as part of the PROMAC project (244244), funded by the Research Council of Norway, and part of the Sustainable Innovation in Food- and Bio-based Industries Programme. Pierrick Stévant was supported by a doctoral fellowship from Sparebanken Møre.
- Bonazzi C, Dumoulin E (2011) Quality changes in food materials as influenced by drying processes. In: Tsotsas E, Mujumdar AS (eds) Modern drying technology, Volume 3: Product Quality and Formulation. Wiley-VCH Verlag, Weinheim Germany, pp 1–20Google Scholar
- Cox S, Gupta S, Abu-Ghannam N (2012) Effect of different rehydration temperatures on the moisture, content of phenolic compounds, antioxidant capacity and textural properties of edible Irish brown seaweed. Food Sci Technol 47:300–307Google Scholar
- Déléris P, Nazih H, Bard JM (2016) Seaweeds in human health. In: Fleurence J, Levine I (eds) Seaweed in health and disease prevention. Academic Press, Amsterdam, pp 319–367Google Scholar
- Fleurence J (2004) Seaweed proteins. In: Yada R (ed) Proteins in food processing. Woodhead publishing, Cambridge, pp 197–213Google Scholar
- ISO:8586:1 (2012) Sensory analysis—general guidance for the selection, training and monitoring of selected assessors and expert sensory assessors. International Organization for Standardization, Geneva Switzerland, pp 28Google Scholar
- ISO:13299 (2003) Sensory analysis—methodology—general guidance for establishing a sensory profile. International Organization for Standardization, Geneva Switzerland, pp 41Google Scholar
- Küpper FC, Carpenter LJ, McFiggans GB, Palmer CJ, Waite TJ, Boneberg E-M, Woitsch S, Weiller M, Abela R, Grolimund D, Potin P, Butler A, Luther GW, Kroneck PMH, Meyer-Klaucke W, Feiters MC (2008) Iodide accumulation provides kelp with an inorganic antioxidant impacting atmospheric chemistry. Proc Natl Acad Sci U S A 105:6954–6958CrossRefPubMedPubMedCentralGoogle Scholar
- Lawless H, Heymann H (2010) Sensory evaluation of food: principles and practices, 2nd edition. Springer, New YorkGoogle Scholar
- Lindsay R (2008) Flavors. In: Demodaran S, Parkin KL, Fennema OR (eds) Fennema’s food chemistry, 4th edition. CRC Press, , Boca Raton, pp 639–687Google Scholar
- Marfaing H, Hemon E, Clement M-J, Sassi J-F, Lerat Y, Chevelot L, Daniel R (2009) Delineating the relationship between the structural features of algal fucoidan and brown seaweed species. Paper presented at the Polymerix, 4th international symposium: biopolymers diversity and industrial applications perspectives, Rennes, France, 28–29 May, 2009Google Scholar
- Michel F, Priol J, Galaup P, Demaimay M, Bigot C (1997) Effet de deux techniques de séchage sur les composés volatils de deux algues alimentaires Ulva sp et Palmaria palmata. Sci Aliments 17:601–617Google Scholar
- R Development Core Team (2017) R: a language and environment for statistical computing. R Foundation for Statistical Computing, Vienna, AustriaGoogle Scholar
- Ragan MA, Glombitza KW (1986) Phlorotannins, brown algal polyphenols. Prog Phycol Res 4:130–230Google Scholar
- Roleda MY, Skjermo J, Marfaing H, Jónsdóttir R, Rebours C, Gietl A, Stengel DB, Nitschke U (2018) Iodine content in bulk biomass of wild-harvested and cultivated edible seaweeds: inherent variations determine species-specific daily allowable consumption. Food Chem 254:333–339CrossRefPubMedGoogle Scholar
- Stévant P, Marfaing H, Duinker A, Fleurence J, Rustad T, Sandbakken I, Chapman A (2017a) Biomass soaking treatments to reduce potentially undesirable compounds in the edible seaweeds sugar kelp (Saccharina latissima) and winged kelp (Alaria esculenta) and health risk estimation for human consumption. J Appl Phycol. https://doi.org/10.1007/s10811-017-1343-8
- Tello-Ireland C, Lemus-Mondaca R, Vega-Gálvez A, López J, Di Scala K (2011) Influence of hot-air temperature on drying kinetics, functional properties, colour, phycobiliproteins, antioxidant capacity, texture and agar yield of alga Gracilaria chilensis. LWT - Food Sci Technol 44:2112–2118CrossRefGoogle Scholar
- WHO/FAO/UNU (2007) Protein and amino acid requirements in human nutrition. WHO Technical Report Series. Report of a joint WHO/FAO/UNU expert consultationGoogle Scholar