Characteristics and functionality of appetite-reducing thylakoid powders produced by three different drying processes

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TY - JOUR

T1 - Characteristics and functionality of appetite-reducing thylakoid powders produced by three different drying processes

AU - Östbring, Karolina

AU - Sjöholm, Ingegerd

AU - Sörenson, Henrietta

AU - Ekholm, Andrej

AU - Erlanson-Albertsson, Charlotte

AU - Rayner, Marilyn

PY - 2018/3/15

Y1 - 2018/3/15

N2 - BACKGROUND: Thylakoids, a chloroplast membrane extracted from green leaves, are a promising functional ingredient with appetite-reducing properties via their lipase-inhibiting effect. Thylakoids in powder form have been evaluated in animal and human models, but no comprehensive study has been conducted on powder characteristics. The aim was to investigate the effects of different isolation methods and drying techniques (drum-drying, spray-drying, freeze-drying) on thylakoids' physicochemical and functional properties. RESULTS: Freeze-drying yielded thylakoid powders with the highest lipase-inhibiting capacity. We hypothesize that the specific macromolecular structures involved in lipase inhibition were degraded to different degrees by exposure to heat during spray-drying and drum-drying. We identified lightness (Hunter's L-value), greenness (Hunter's a-value), chlorophyll content and emulsifying capacity to be correlated to lipase-inhibiting capacity. Thus, to optimize the thylakoids functional properties, the internal membrane structure indicated by retained green colour should be preserved. This opens possibilities to use chlorophyll content as a marker for thylakoid functionality in screening processes during process optimization. CONCLUSION: Thylakoids are heat sensitive, and a mild drying technique should be used in industrial production. Strong links between physicochemical parameters and lipase inhibition capacity were found that can be used to predict functionality. The approach from this study can be applied towards production of standardized high-quality functional food ingredients.

AB - BACKGROUND: Thylakoids, a chloroplast membrane extracted from green leaves, are a promising functional ingredient with appetite-reducing properties via their lipase-inhibiting effect. Thylakoids in powder form have been evaluated in animal and human models, but no comprehensive study has been conducted on powder characteristics. The aim was to investigate the effects of different isolation methods and drying techniques (drum-drying, spray-drying, freeze-drying) on thylakoids' physicochemical and functional properties. RESULTS: Freeze-drying yielded thylakoid powders with the highest lipase-inhibiting capacity. We hypothesize that the specific macromolecular structures involved in lipase inhibition were degraded to different degrees by exposure to heat during spray-drying and drum-drying. We identified lightness (Hunter's L-value), greenness (Hunter's a-value), chlorophyll content and emulsifying capacity to be correlated to lipase-inhibiting capacity. Thus, to optimize the thylakoids functional properties, the internal membrane structure indicated by retained green colour should be preserved. This opens possibilities to use chlorophyll content as a marker for thylakoid functionality in screening processes during process optimization. CONCLUSION: Thylakoids are heat sensitive, and a mild drying technique should be used in industrial production. Strong links between physicochemical parameters and lipase inhibition capacity were found that can be used to predict functionality. The approach from this study can be applied towards production of standardized high-quality functional food ingredients.

KW - chloroplast membrane

KW - drying

KW - lipolysis

KW - physicochemical properties

KW - spinach

U2 - 10.1002/jsfa.8627

DO - 10.1002/jsfa.8627

M3 - Article

VL - 98

SP - 1554

EP - 1565

JO - Journal of the Science of Food and Agriculture

T2 - Journal of the Science of Food and Agriculture

JF - Journal of the Science of Food and Agriculture

SN - 1097-0010

IS - 4

ER -