De Leyn, Ingrid

Debonne, Els

Eeckhout, Mia

Samapundo, Simbarashe

Van Bockstaele, Filip

Vroman, Annemarie

Wagemans, K

English

Ghent University Academic Bibliography

Impact of frozen storage and defrosting on the qualityand safety of bakery productsF. Van Bockstaele1,2 , E. Debonne1,2,3, K. Wagemans4, I. De Leyn1,2, S. Samapundo1,3, A. Vroman1,3, M. Eeckhout1,2,31 Ghent University, Faculty of Bioscience Engineering, Departement of Applied Biosciences, Valentin Vaerwyckweg 1, B-9000, Ghent2 Laboratory of Cereal Technology - 3 Laboratory of Applied mycology4 Federatie van Grote Bakkerijen in België, vzw-asbl, BelgiumProblem settingEU regulation No. 1169/2011 states that for foods that have been frozen before sale and which are sold defrosted, the name of the food shall be accompanied by the designation‘defrosted’. This requirement does not apply for foods for which defrosting has no negative impact on the safety or quality of the food, such as bakery products. However, producersshould be able to clearly show that defrosting has no negative impact on the quality and safety of the bakery products.GoalThe impact of temporary frozen storage and defrosting on the quality and safety of a selection of industrially produced bakery products (whole wheat bread, sandwiches, sponge cake (with cream and fruit filling), bake-off bread and cherry pie) was studied in comparison with non-frozen products.ConclusionThe impact of temporary frozen storage of bakery products on product quality and safety was not always negative or even visible. For bread, the impact on quality was minimal and led to a decrease in microbial load. A significant reduction in microbial load was also found for sandwiches at the end of the shelf life time. Safetywise, the impact of temporarily frozen storage of the tested bakery products was negligible or even improved.The main impacts of temporarily frozen storage on product quality were reported on sandwiches and cherry pie. Despite of the fact that differences in quality were perceived, the consumer’s acceptability of the products did not significantly decrease. It could be concluded that the impact of temperarily frozen storage of bakery products can not be catalogued as being negative.Water activity (aw) (25 °C)  No significant differences between fresh and frozen products of the following categories were reported: bread, sponge cake, bake-off bread and cherry pie.Only for sandwiches, frozen storage impacted the aw of the crust on T0 (delivery date of sandwiches, either fresh or frozen). No significant difference remained visible after 4 days (T0 + 4d) (crust aw ≈ 0,921). .Texture of bread productsThe impact of frozen storage anddefrosting on the crumb of the whole wheat bread, sandwich andbake-off bread was investigatedusing a Texture Analyzer (TextureProfile Analysis – TPA). aw sandwich Fresh T0 Frozen T0Upper crust 0,921 ± 0,008 0,878 ± 0,022Bottom crust 0,918 ± 0,003 0,898 ± 0,015SafetyLegend:Blue:       : fresh productYellow:         : frozen + defrosted before T0: Upper limit of acceptibility: significant difference between fresh andfrozen productT0 : Delivery date (fresh or frozen)Challenge test with spoilage fungiNo significant differences were observed between fresh and frozen bakery products in a challenge test. Each bakery product was inoculated with specific mould spore solutions and incubated for a selected time. The number of incubation days needed for growth of the microorganisms was recorded.Bakery productOrganism Incubation(days)Bread crust Penicillium paneum >7Bread crumb 3Sandwiches 7Sponge cake Eurotium amstelodami>15Cherry pie 7Bakery product Parameter Fresh Frozen Fresh FrozenBread(S = 3 d)T0 T0 + SHardness (g) 487 ± 63 a 480 ± 40 a 541 ± 48 a 538 ± 40 aCohesion (-) 0,75 ± 0,01 a 0,71 ± 0,01 b,c 0,73 ± 0,01 a,b 0,69 ± 0,01 cBake-off bread(S = 34 d)Hardness (g) 378 ±96 a 441 ± 83 a 367 ± 46 a 411 ± 81 aCohesion (-) 0,80 ± 0,02 a 0,78 ± 0,02 a 0,83 ± 0,01 b 0,82 ± 0,01 bSandwich(S = 4 d)Hardness (g) 240 ± 33 a 236 ± 39 a 419 ± 46 b 428 ± 37 bCohesion (-) 0,63 ± 0,02 a 0,55 ± 0,04 b 0,50 ± 0,02 c 0,43 ± 0,02 dTotal plate count measurementSensorial evaluationThe sensorial evaluation was performed by a triangle test. The resultsshow that for some bakery products a difference between fresh andfrozen/defrosted was observed. However this difference was notalways perceived as negative as for some products the acceptability didnot decrease. Differences between fresh and frozen products could bedue to a batch effect.• Numbers with equal letters within the same parameter are not significantly different (SPSS Anova, α=0,05)• T0: delivery date of the product, either fresh or frozen• S: number of storage days, depending on the productSignificant difference? Acceptability (%)Bakery product @ T0 @T0 + S @ T0 @ T0 + SBread(S = 3 d)No No79 61Bake-off bread(S = 34 d)No No87 70Sandwich(S = 4 d)Yes No92 100Sponge cake(S = 2 d)Yes Yes80 94Cherry pie(S = 4 d)No Yes79 83Quality0 5 10 15 20 25 30 351200110010009008007006005004003002001000-100Force (g)Time (sec)1 2 3 4 5 61F2FF rce (g)Time (sec)LegendSponge cake

Impact of frozen storage and defrosting on the quality and safety of bakery products

https://biblio.ugent.be/publication/8136241/file/8151387

Impact of frozen storage and defrosting on the quality and safety of bakery products

Abstract

Similar works

Full text

Available Versions

Ghent University Academic Bibliography