Naslov
Impact of biscuits composition and baking procedure on polyphenolic content and bioaccessibility

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, 327-327

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
biscuits; polyphenols; bioaccessibility; baking

Sažetak
Since cereal-based confectionary products become even more recognized as functional foodstuff with improved nutritive characteristics, there is a general pursuit of increasing their content of different health protecting substances such as polyphenols, dietary fibers, vitamins and minerals. Therefore, in the frameworks of this research six different types of nutritionally improved biscuits, experimentally prepared in a laboratory conditions, were evaluated as sources of health protective polyphenolic substances. The goal of the investigation was to assess the significance of implementing different types of integral raw materials or dietary fibers to wheat flour based recepture on polyphenolic content in the final product. Raw materials used for enrichment of standard recepture were soy flour, carob, amaranth, apple dietary fiber or oat dietary fiber. In order to investigate the impact of baking procedure on the levels of phenolic compounds, respective dough samples were analyzed as well. Phenolic content was determined in defatted samples using Folin-Ciocalteu spectrophotometric method. Results obtained after chemical extraction with acidified methanol/water mixture indicated that significant increase of polyphenolic content can be achieved by implementing some of the used whole grain raw materials or dietary fibers to standard recepture. Phenolic content (expressed as ferulic acid equivalents) ranged from 58 mg/100g (sample with oat fiber) to 387 mg/100g (sample enriched with carob). Obtained results dealing with the impact of baking procedure on phenolic content where somewhat confusing since in some samples it has been observed that baking procedure significantly increases the content of phenolic compounds. The highest increase was observed in samples containing apple fiber, soy flour or carob (127 %, 119 % and 118 % respectively). Due to the lack of literature data it was impossible to compare our results to the findings of other authors. However, knowing that usual chemical extractions only liberate a part of total phenolics present in a food sample, we have concluded that baking procedure probably liberated some of hydrolizable phenolics of the sample so that they became extractable in used extraction solvent. We have proven our theory by determining hydrolizable phenolic fraction in all dough- and biscuits samples and calculating the total amount of phenolic compounds (extractable + hydrolizable).Taking into account total phenolic content, our final results revealed that baking doesn't significantly influence total phenolic content in biscuits regardless of their composition (averagely 5.7 %, p>0.05). Increased polyphenolic content is certainly a desirable characteristic of a nutritionally improved foodstuff, due to their antioxidative and other health protective characteristics. However, in order to excrete their beneficial activity, polyphenols must be accessible for intestinal absorption from the foodstuff. Therefore, bioaccessible phenolic fraction was also estimated in investigated doughs and biscuits, by analyzing the samples after in vitro simulation of gastrointestinal digestion using digestive enzymes. Obtained results revealed significant differences among investigated samples, increase of bioaccessibility during baking procedure (8.9 – 59.7 %) and proved that usual chemical approaches for estimation of polyphenols might underestimate the actual amount of bioaccessible phenolic compounds in these types of samples.

Izvorni jezik
Engleski

Znanstvena područja
Farmacija

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