High fibre breads were produced adding durum wheat bran fractions of different composition and particle size. Fresh products were characterized for texture, crumb grain, volume, colour, water status ...(water activity, moisture content, frozen water content, 1H molecular mobility).
The addition of bran fractions with different composition resulted in significantly harder samples with lower volumes as compared to the control (STD), while bran fractions with different particle size did not significantly affect the volume and hardness of the samples (comparable to STD).
The addition of bran fractions with different composition and particle size resulted in an altered water status, as shown by crumb moisture content (∼43% vs ∼41% in STD), water activity (0.97 vs 0.96 in STD) and frozen water content (∼60–66% vs ∼51% in STD). 1H NMR data showed an altered 1H molecular mobility in bran breads as compared to STD. In particular, an additional 1H T2 population was found in the bran samples. This population has been related to the influence of bran on starch-gluten-water interactions.
► We studied bread formulations that include a source of dietary fibre (bran). ► Different bran fractions (different composition and particle sizes) are added to bread. ► All bran fractions affect bread properties at different levels of analysis. ► Bran fractions affect molecular mobility, as showed by an additional 1H T2 population.
Bread staling is a complex phenomenon that originates from multiple physico-chemical events (amylopectin retrogradation, water loss and redistribution) that are not yet completely elucidated. ...Molecular properties of white bread loaves were characterized by multiple proton Nuclear Magnetic Resonance (NMR) techniques (proton FID, T
2 and T
1 relaxation time) over 14 days of storage. Changes at a molecular level (faster decay of proton FIDs and shifting of proton T
2 relaxation times distributions towards shorter times), indicating a proton mobility reduction of the bread matrix, were observed during storage. Multiple
1H T
2 populations were observed and tentatively associated to water-gluten and water-starch domains. Proton T
1 of bread was for the first time measured at variable frequencies (Fast Field Cycling NMR) and found to be strongly dependent upon frequency and to decrease in bread during storage, especially at frequencies ≤ 0.2 MHz. An additional proton T
1 population, relaxing at 2 ms, was detected at 0.52 MHz only at early storage times and tentatively attributed to a water-gluten domain that lost mobility during storage.
Physicochemical properties and water status of fresh pasta (both extruded and laminated) produced with recently designed mixers (Premix
® and Bakmix
®) that induce a uniform hydration of the solids ...and allow the formation of a dough in 1–2
s were evaluated.
Different mixers affected the physicochemical properties considered more markedly in the extruded than laminated products. Fresh pasta produced with Premix
® and Bakmix
® was less extensible and harder (extruded samples) and exhibited higher solids loss during cooking than the control. The water status of fresh pasta was not affected by mixing in laminated products, whilst a stronger water–solids interaction (both at macromolecular (FW) and molecular (faster FID decay, larger% Pop A, bimodal T
1 distribution) levels) was induced by the new mixers in the extruded products. Premix
® and Bakmix
® did not allow the development of a plastic and extensible continuous phase due to the shorter mixing time and/or different (lacking) kneading action and/or lower water available for proper gluten development.
Fiore Sardo (FS), a traditional Italian cheese, is present in the market as a heterogeneous variety of products. The use of heat-treated (HT) milk is forbidden by the official production protocol, ...but no official analytical method able to detect heat application is yet available. Here, a combined magnetic resonance imaging (MRI) relaxometry and image analysis approach to recognize FS made from raw milk is presented. Artisanal FS cheeses were produced from raw milk (RC) by five shepherds in accordance with the official protocol. They were compared to HT-milk counterparts (HTC). Additionally, industrially manufactured commercial FS cheeses (I) were also purchased and compared to RC and HTC. Relaxometry data of FS indicated the presence of two water populations; the ratio of characteristic relaxation time constant T2 and area fraction (Score, Ṩ) of the fastest relaxing population was used to compare RC, HTC and I samples. RC from HTC were successfully discriminated, the latter exhibiting lower Ṩ (enhanced protein hydration). I cheeses exhibited the lowest Ṩ values, sometimes comparable to HTC. Since visual appearance of RC and HTC is appreciably different, an image analysis deep learning approach using MRI and photographic pictures was adopted to discriminate the two productions, with promising percentages (>93%).
Fresh pasta is a very common food in Italy and it can be produced by subjecting a semolina-water dough to either to extrusion or lamination (recently under vacuum) to obtain the desired shape. Very ...little information is available on the effect of shaping on properties of fresh pasta. The objective of this work was to evaluate the effect of the extrusion, lamination and lamination under vacuum on selected fresh pasta physico-chemical properties.
Different shaping modes significantly (
p
<
0.05) affected macroscopic properties: laminated products were more yellow and exhibited lower solids loss during cooking than the extruded products. Laminated fresh pasta was less tenacious and less extensible than extruded fresh pasta. Application of vacuum during lamination improved “fresh pasta quality” indicators: it was more yellow, tenacious and extensible than fresh pasta that underwent traditional lamination.
The water status (macroscopic and molecular) of fresh pasta was only slightly affected by the shaping process.
Four gluten-free (GF) breads produced using commercial GF mixes with different formulations were characterized during 1 week of storage and compared to wheat-flour-based bread (STD), in terms of ...texture (texture profile analysis), amylopectin retrogradation (differential scanning calorimetry) and water status (moisture content, frozen water content by differential scanning calorimetry and
1
H nuclear magnetic resonance—NMR mobility by a low-field spectrometer). GF fresh breads were significantly harder, less cohesive and less springy than STD. Water status indicated higher water availability in GF breads, depending on formulation, with higher moisture and frozen water content that was also reflected in a higher molecular mobility (
1
H spin–spin NMR relaxation time). Furthermore, limited changes in moisture and frozen water contents were observed in GF bread, and therefore, textural changes in these GF products were mostly related to retrograded amylopectin. Statistical analysis with PCA (principal component analysis) allowed to identify the most important factors in the GF bread staling process. The effect of formulation (GFs vs STD) was related to water status descriptors and the effect of storage to textural properties, retrograded amylopectin parameters, as well as the mobility of the more rigid protons.
The quality of Protected Designation of Origin (PDO) Fiore Sardo, an Italian cheese, is investigated by Time-Domain Nuclear Magnetic Resonance (TD-NMR) relaxometry. In this work, artisanal and ...industrial products are analysed in terms of relaxometric parameters to describe their quality. Artisanal cheeses were produced from raw milk (RC) by five shepherds, as indicated by following the official protocol. Heat-treated milk cheeses (HTC) counterparts were produced with the same manufacturing process. Commercial industrial cheeses (IND) were also analysed and compared to RC and HTC. TD-NMR relaxometry parameters are able to describe Fiore Sardo quality (RC, HTC and IND cheeses). The characteristic variability of artisanal productions is properly highlighted, and the influence of milk heat treatment and industrial processing is clearly observable in HTC and industrial cheeses as highlighted by TD-NMR relaxometry parameters. TD-NMR relaxometry can potentially be exploited in quality-control practices in the dairy sector, as a valid alternative to more sophisticated analytical techniques.
Escherichia coli possesses five known DNA polymerases (pols). Pol III holoenzyme is the cell's main replicase, while pol I is responsible for the maturation of Okazaki fragments and filling gaps ...generated during nucleotide excision repair. Pols II, IV and V are significantly upregulated as part of the cell's global SOS response to DNA damage and under these conditions, may alter the fidelity of DNA replication by potentially interfering with the ability of pols I and III to complete their cellular functions. To test this hypothesis, we determined the spectrum of rpoB mutations arising in an isogenic set of mutL strains differentially expressing the chromosomally encoded pols. Interestingly, mutagenic hot spots in rpoB were identified that are susceptible to the actions of pols I-V. For example, in a recA730 lexA(Def) mutL background most transversions were dependent upon pols IV and V. In contrast, transitions were largely dependent upon pol I and to a lesser extent, pol III. Furthermore, the extent of pol I-dependent mutagenesis at one particular site was modulated by pols II and IV. Our observations suggest that there is considerable interplay among all five E. coli polymerases that either reduces or enhances the mutagenic load on the E. coli chromosome.
Physico-chemical properties and volatile compounds of three commercial Altamura breads were evaluated during storage at 25
°C. Two protected denomination of origin (PDO) artisanally produced Altamura ...breads (Bari, Italy), characterized either by high (High A) or low (LowA) loaf, and an industrial product, commercialized as “Altamura like” (IndA), were studied.
HighA and LowA breads had a tick crust that was also detached from the crumb creating an air cushion between crust and crumb. IndA products had a thinner crust, a more homogeneous crumb structure as well as a more homogeneous water distribution among the different portion of the bread loaf than HighA and LowA. A more pronounced water gradient characterized the artisanal breads. Crust and under crust portion of all breads, and crumb for IndA product, underwent a significant reduction of moisture content and
a
w during storage. Both artisanal breads were subjected to a more significant crumb hardening than IndA sample. Fresh crusts of artisanally produced breads were also significantly harder than IndA. Fresh IndA samples were significantly less cohesive and less springy than artisanal products; cohesiveness significantly decreased in all samples during storage. A more complex gas chromatographic profile was found in the artisanal bread as a larger amount of volatile compounds was present as compared to the IndA bread. Volatile compounds originated both from microbial activity and non-enzymatic browning. Larger amount of volatile compounds characteristics of yeast fermentation was found in IndA. Volatiles decreased over storage in both samples, more significant in the IndA product.
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