Dubravka Novotni

Glycemic index and phenolics of partially-baked frozen bread with sourdough

Different lactic acid bacteria starters were used to prepare sourdough to make partially-baked frozen wholemeal wheat bread. The sourdough was prepared with a pure culture of Lactobacillus plantarum or with commercial starters containing Lactobacillus brevis combined with Saccharomyces cerevisiae var. chevalieri (LV4), Lactobacillus fermentum (PL1), or Lactobacillus fermentum with phytase (PL3). We determined the acetic and lactic acid concentrations in sourdough, bread chemical composition, total phenolics content and glycemic index (GI) in vivo. Depending on the starter, the lactic to acetic acid ratio in the sourdough was significantly different. The GI of control bread without sourdough (70) was significantly higher than that of bread containing sourdough prepared with LV4 starter (50), PL1 starter (56) or PL3 starter (56), but not from bread with L. plantarum sourdough (60). The addition of 10% sourdough with a lower molar ratio of lactic to acetic acid ( ≤ 4) and higher total phenolics content is preferable for generating bread with medium and low GI.

Identification and quantification of lignans in wheat bran by gas chromatography-electron capture detection.

Whole grain cereals are an important source of bioavailable lignans, the group of compounds with potential anti-cancerogenic, antioxidant, anti-proliferative, pro-apoptotic, and antiangiogenic properties. The aim of this work was to develop a sensitive method for determination of wheat bran lignans. The analysis of lignans secoisolariciresinol, hydroxymatairesinol, lariciresinol, matairesinol, pinoresinol, syringaresinol is based on derivatization with pentafluoropropionic anhydride (PFPA) and gas chromatography-electron capture detection (GC-ECD), using styrene glycol as internal standard. To our knowledge, this is the first time that EC detection has been used for lignan analysis. The results show that the technique is reproducible and sensitive enough for detecting lignans in wheat at parts-per-billion (ppb) levels, except for hydroxymatairesinol. The method developed showed good recovery (85-105%) and precision (4-20%) for five types of lignans and thus represents a simpler and more affordable alternative to state-of-the-art wheat lignan liquid chromatography tandem mass spectrometry (LC-MS/MS) analysis.

Market potential of lignans and omega-3 functional cookies

Purpose Cookies were not generally viewed as functional contributors to well-being as they are primarily perceived as confectionery products. The purpose of this paper is to evaluate the potential of flaxseed-enriched cookies as carriers of lignans and omega-3 fatty acids – functional compounds that are lacking in the western diet. Design/methodology/approach An online questionnaire collected data from Croatian consumers (n=1,035). The majority of the samples were women (73 per cent) in the age range 15-65 years (97 per cent). Most participants were employed, had a higher education degree, and lived in urban areas. Questions examined the consumption of cookies and flaxseed, interest for functional cookies, nutritional knowledge, and awareness. Findings Majority of subjects consumed cookies (93 per cent), while 61 per cent did not eat flaxseed or ate it less than once a month. The consumers showed elevated interest for the functional cookies with flaxseed, among which elderly women with higher nutrition awareness, and nutrition knowledge were the most interested. Functional cookies with flaxseed could be used for delivery of lignans and omega-3 fatty acids in everyday diet, but in order to reach wider range of consumers producers might benefit from employing nutritional educational marketing campaigns. Originality/value Data from the study decreased scarcity of information on consumer behaviour related to flaxseed consumption and on potential use of cookies as a functional food. Reported findings will be useful to dieticians, food industry, and food researchers in countries with a high prevalence of cookie consumption.

Freezing of Bread

Freezing of bread, especially partially baked, is todays common practice in the bakery industry. The introduction of freezing in the conventional bread making process resulted with the extreme prolongation of bread shelf-life, reduced bread waste and related economical losses, increased bread diversification, and gave consumers fresh bread at any time of the day. While benefits of bread freezing are many, the process also faces different drawbacks and challenges that need to be overcome. Both positive and negative sides, as well as the energy efficiency of this undoubtedly growing technology will be discussed in this chapter.

Influence of Barley Sourdough and Vacuum Cooling on Shelf-Life Quality of Partially Baked Bread

Driven by the bakery industry urge to satisfy consumer demand for fresh, diverse and high quality bakery products, we investigated the influence of barley sourdough and vacuum cooling on shelf life quality of partially baked bread stored in modified atmosphere packaging at ambient conditions. Barley sourdough was fermented with Lactobacillus reuteri (DSM 20016, F275). Partially baked bread with sourdough was microbiologically acceptable during 30 days of storage, while bread without sourdough had detectable mould on the 30th day. Stored bread samples were rebaked after 1, 8, 15, 22 and 30 days to determine moisture content, physical and sensorial properties. Moisture loss (5%) was detected on the 15th day, after which it remained stable until the end of investigated storage period. Nevertheless, textural quality of stored bread continuously declined due to crumb firming. Bread flavour did not change during mould-free storage time. The principal component analysis identified major differences in the flavour of sour and control bread, also in crumb firmness and moisture content of samples. This study indicates the positive role of barley sourdough fermented with L. reuteri in improving crumb texture for at least 15 days, and ensuring mould- and bacteria-free partially baked bread for 30 days. Vacuum cooling combined with sourdough improved bread shape, porosity, and reduced sour taste, crust colouring and crumbliness. Hence, it can successfully extend shelf life quality of partially baked bread in modified atmosphere packaging.

Frozen stored barley sourdough: stability and application to wheat bread

The primary aim of the industrial use of sourdough is to improve bread quality and to replace additives. This study investigates the applicability of frozen stored barley sourdough in wheat bread. Sourdough was fermented with Weissella cibaria in the presence of sucrose and xylanase, and stored frozen for 4, 8, or 12 weeks. During storage, the number of viable cells in the sourdough declined. Softer dough and crumb were obtained after the sourdough was stored for a longer period (4 weeks), while bread specific volume was unaffected by the sourdough storage time. The highest bread specific volume, shape, crumb softness, and sensory liking were obtained with 20% of the sourdough. This study demonstrates the possibility for the industrial application of frozen barley sourdough, since it can improve the quality of bread compared to the native barley flour.