Naslov
Different approaches to estimation of antioxidant capacity of biscuits

Autori
Vitali, Dubravka ; Vedrina-Dragojević, Irena ; Šebečić, Blaženka

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, sažetak, znanstveni

Izvornik
Cereals worldwide in the 21st century: present and future, Cerworld 21st, Book of abstracts / Poms, R. E. ; Collar, C. - Madrid : AETC-Spanish Association for Cereal Science and Technology, 2008, 249-249

ISBN
978-84-612-4517-8

Skup
13th ICC Cereal and Bread Congress

Mjesto i datum
Madrid, Španjolska, 15.06.2008. - 18.06.2008

Vrsta sudjelovanja
Poster

Vrsta recenzije
Međunarodna recenzija

Ključne riječi
biscuit; FRAP; ABTS; antioxidant capacity

Sažetak
Due to high daily intake, cereal-based food represents the most important source of certain antioxidant compounds (phenolic compounds, phytic acid) that have been proven to lower the risk of developing a wide range of diseases such as age related processes, cardiovascular diseases and certain types of cancer. There are lots of possible in vitro approaches for estimation of antioxidant potential of a foodstuff - the measurement of radical scavenging activity (superoxide anion-, hydroxyl- and free radical scavenging activity on DPPH˙ or ABTS˙+) ; antioxidant activity in linoleic acid emulsion system ; ferric reducing power ; chelating capacity etc. The most important limitation of such procedures is incomplete extraction of antioxidant substances from the foodstuff – usually mixtures of certain organic solvents with water are used. However, it is doubtful if obtained results accurately reflect antioxidant activity of investigated foodstuff in physiological conditions even when optimal extraction solvent is found. Therefore, in this investigation two types of extraction procedures were applied for estimation of antioxidant potential of six different types of integral hard biscuits. Chemical extraction was conducted using acidified water/methanol extraction solvent that was chosen based on our preliminary investigations, and physiological approach included in vitro simulation of gastrointestinal digestion using different digestion enzymes. Antioxidant activity of biscuits was assessed using two spectrophotometric methods – estimation of ferric reducing power (FRAP) and measurement of 2, 2’ -azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS˙+) radical cation scavenging activity. Biscuits were experimentally prepared in laboratory conditions by supplementing standard wheat based recepture with carob, amaranth, soy flour, apple- or oat dietary fiber, respectively. The goal of our investigation was to compare chemical and physiological approaches for estimation of antioxidant activity as well as to assess the impact of biscuits’ composition and baking procedure on the content of substances excreting antioxidant activity in the final product. ABTS˙+ radical scavenging activity of the samples was expressed as μ gTrolox/100 mg of sample and ferric reducing power was expressed as mg of sample excreting the same activity as 1 mmol Fe (II). Our results revealed that baking significantly increased both types of antioxidant activity in both, chemical and physiological extracts probably because baking also increased the amounts of extractable phenolic compounds known as bearers of antioxidant potential in cereal based foods. Antioxidant activity of biscuits’ chemical extracts ranged from 134 μ gTrolox/100 mg i.e.1268 mg/mmol Fe(II) (sample with oat fibers) to 503 μ gTrolox/100 mg i.e.381 mg/mmol Fe(II) (sample with carob). Physiological and chemical approach revealed very similar results regarding the ferric reducing power while at the same time ABTS˙+ radical scavenging activity of physiological extract was significantly higher compared to chemical extract ranging from 160 (sample with oat fiber) to 590 μ gTrolox/100 mg (sample with carob). Although our results indicate that chemical approach actually underestimates the radical scavenging activity of investigated samples, it is obvious that results obtained in chemical extracts correlate well with physiological antioxidant activity and reflect rather well the differences in antioxidant activity among biscuits with different raw-materials composition.

Izvorni jezik
Engleski

Znanstvena područja
Farmacija

POVEZANOST RADA