3.2.5. The Farinograph Quality Number

The values of the farinographic quality number (QN), resulting from Rp additions, are presented in Table 2. It was observed that the QN of samples with added Rp were generally higher than the control sample, except for the sample with an addition of 2.0% Rp, which had the same value (116). The dough obtained from WF with 2 g AA/100 kg had a QN equal to 121, between 1.0% and 1.5% Rp. However, the differences were not significant (*p* > 0.05).

Although no clear correlation can be established between the addition of Rp and the value of the QN, the fact that the QN was higher than the control sample showed that the Rp addition had a positive influence on the QN. This statement is consistent with findings observed by Nikoli´c et al. [69], who obtained a QN of 52.8 ± 2 for wheat flour (control) and increased values of 67.8 ± 2 for 30% buckwheat flour/100 g flour mixture.

#### *3.3. Bread Characterization*

The physico-chemical properties of bread made from WF, WF–Rp, and WF with AA as the improver are shown in Tables 3 and 4.


**Table 3.** Physical properties of bread (height, weight, and volume).

WF—wheat flour, Rp—rosehip powder, WF–Rp—mixtures of wheat flour with rosehip powder, WF–AA—wheat flour with ascorbic acid addition of 2 mg/100 g. Different letters within the column indicate the values are statistically different at a 95.0% confidence level.

**Table 4.** Physico-chemical properties of bread crumb.


WF—wheat flour, Rp—rosehip powder, WF–Rp—mixtures of wheat flour with rosehip powder, WF–AA—wheat flour with ascorbic acid addition of 2 mg/100 g. Different letters within the column indicate the values are statistically different at a 95.0% confidence level.

#### 3.3.1. Bread Dimensions

Although the dough was baked in trays, the bread dimensions were measured. It was observed from the beginning that the leavening was differentiated, resulting in pieces of bread of different heights, most likely due to the Rp addition's influence. The values of length (around 235 mm) and width (about 91 mm) of bread did not differ significantly (*p* > 0.05) due to baking in trays. In contrast, the height of the loaves, determined as an average of two duplicates, showed significant differences (*p* < 0.05) (Table 3).

#### 3.3.2. Bread Volume

The volume and specific volume of bread are reported in Table 3.

The bread volume had higher values for samples with added Rp compared to the control (486 ± 4.24 cm3), except for the addition of 0.5% Rp. The most significant increase in volume was observed for 1.0% and 1.5% Rp, while for the following additions, there was a slight decrease, but the values remain higher than for control. The bread volume with ascorbic acid (WF–AA) had a value between the bread volumes with the addition of 1.0% and 2.0% Rp. According to the ANOVA, the differences were significant (*p* < 0.05). The increase in bread volume could be explained by the Rp addition, which provided the dough with a specific content of AA that contributed to dough stabilization, gluten network strengthening [26,27], and a larger volume of bread [28].

The bread volume is, for most consumers, one of the main criteria for evaluating the bread quality and is implicitly one of the primary decision-making elements of purchasing. Hathorn et al. [78] considered that the importance of bread volume for consumers derives from their desire to consume bread that seems light and not too dense. Thus, even if a large volume is not desirable, consumers associate large volumes with some loaves of bread and small values with others, e.g., flat chapatti, Lebanese bread, and pita bread.

From a technological point of view, the bread volume is an essential external feature as it represents a quantitative measure of the performance of the baking process [79]. The bread volume depends on the quantity and quality of gluten [73] and how the dough is processed. Thus, a well-kneaded and developed dough with a well-formed gluten network will reduce the loss of gas and contribute to an increased bread volume [1]. Moreover, the volume of bread correlates with the moisture of the dough. Thus, Gallagher et al. [80] stated that higher moisture located in the optimal area positively influences bread volume because the bread will have an increased volume.

Osuna et al. [81] studied the composition, sensory properties, and the effects of ascorbic acid and α-tocopherol additions on the oxidative stability of wholemeal bread and vegetable oils. Although they stated that adding AA contributed to increasing the bread volume by improving the dough's stability, the authors did not determine the specific volume or bread volume.

Hallén et al. [82] added chickpea flour obtained from grains, germinated and fermented, in a proportion of 5%, 10%, and 15% to wheat flour. For some additions they obtained increases in the volume of bread loaves compared to the control (1560 mL), for example, an increase up to 1657 mL for the addition of 5%, 1598 mL for 10%, and 1627 mL for 15% chickpea flour; 1667 mL for 5% and 1587 mL for 10% germinated chickpea flour; and 1710 mL for 5% and 1680 mL for 10% fermented chickpea flour. For the rest of the additions, the specific volume was lower than the control. Most of the volume increases were small because the addition of chickpea flour resulted in a stickier dough that was more difficult to process, especially in the case of sprouted chickpeas, due to the reduced content of gluten-forming proteins. The bread obtained was generally more compact, with a denser structure [82].

In a similar study, McWaters et al. [83] added chickpea flour from raw and extruded grains in 15% and 30% proportions. They recorded a decrease in volume for all additions compared to the control. The reduction in volume was higher for the 30% addition compared to 15%, and the reduction in volume was also higher for the flour from extruded chickpea grains due to the decrease in the content of gluten-forming proteins even if the total protein content of the flour mixes increased.

Van Hung et al. [48] stated that the addition of fibre dilutes proteins and interferes with forming the optimal gluten network, confirming the previous statements.

Yamasaengung et al. [84] continued these studies by combining chickpea flour with emulsifiers. If no emulsifier was added to the white bread, the specific volume of the bread was significantly smaller (*p* < 0.05). Therefore, they stated that only emulsifiers significantly affected the specific volume of white bread (*p* < 0.05). The decrease in bread volume caused by chickpea flour can be counteracted by increased water in the dough. In wholemeal bread, the volume increase is influenced by a combined effect of water and emulsifiers [84]. In general, bread volume is correlated with a soft texture and high porosity, while bread density refers to a more compact, harder-textured bread [84].

The inverse of the density, expressed in g/cm3, is the specific volume in cm3/g. This parameter results from the calculation that relates the total volume of a loaf of bread to its mass, and it presents the same evolution as the volume of bread. Thus, bread with the addition of Rp had higher values of the specific volume than the control, except for the 0.5% addition of Rp. Sheikholeslami et al. [85] reported a slight increase in the specific volume of bread obtained from wheat flour with the addition of 10% and 20% barley flour with a low proportional coating content for smaller mesh sizes, thus retaining more coating particles with the addition of guar gum. The highest value of the specific volume was obtained for sieve 40 with the addition of 1% guar gum (2.90 ± 0.20 cm3/g) compared to the control (2.70 ± 0.17 cm3/g), and was lower for sieve 50 with the addition of 20% barley flour with a low coating content, without the addition of guar gum (2.10 ± 0.17 cm3/g). Instead, Hathorn et al. [78] obtained a specific volume reduction from 1.7 cm3/g to 1.4 cm3/g when adding 50% to 65% sweet potato flour.

In other studies, higher specific bread volumes were reported, for example, 3.3–4.0 cm3/g for bread prepared with the addition of heat-treated maitake mushroom powder [86], and 3.4–4.4 cm3/g for wheat bread with added dextrins [87].

#### 3.3.3. Bread Moisture and Acidity

A higher moisture retention in bread is economical and is also required to lengthen shelf life [88].

A higher moisture content was found in bread prepared from WF–Rp mixtures compared to the control (41.81 ± 0.40%). The differences were significant (*p* < 0.05). The increase in bread moisture was probably determined by the increase in the water absorption of WF–Rp mixtures due to the higher fibre content of Rp. However, the bread moisture of samples with an addition of 2.5% Rp and AA as an improver did not follow the increasing tendency, as they were situated between the moistures of the control and the sample with the addition of 0.5% Rp. This might be expected, as several factors not determined in this study could influence the moisture content of bread.

Similar results are reported in the literature. Toasted bread with a high fibre content was obtained by adding 10%, 20%, and 30% of fine or coarse bran that was dark or light in colour, and wheat germ. The bread had a higher moisture content than the bread obtained from unbleached wheat flour (39.29 ± 0.34%) for all types of bran. The increase in moisture was explained by the higher amounts of water used to prepare the dough for samples with bran fractions [88]. Sidhu et al. observed that moisture content was slightly higher for bread with increasing levels of bran addition (10–30%) [89]. Another study reported an increase in moisture with increased levels of polyols [88]. They found a higher moisture content in bread prepared after the incorporation of 4% sorbitol as compared to the control.

Bread acidity (Table 4) values increased for all breads compared to the control (2.0 acidity degrees), reaching 2.25 ± 0.07 acidity degrees for bread prepared with WF–Rp with the 2.5% Rp addition. The differences were not significant (*p* > 0.05) according to the ANOVA one-way statistical analysis. Ascorbic acid is consumed during kneading, and if it somehow remains in excess in the dough, it will be distorted when baked. Other components of Rp, such as the organic acids of rosehip composition, may be responsible for the values obtained for acidity. This issue will be followed in future research.

#### 3.3.4. Bread Crumb Porosity and Elasticity

The breads obtained were characterized by high porosity values (Table 4). Higher porosity was found in bread prepared from WF–Rp mixtures compared to the control (87.75 ± 1.06%), except for the porosity of bread with an addition of 0.5% Rp (87.50 ± 0.71%), which was slightly lower. The porosity values increased by 1.0% and 1.5% with the addition of Rp, then slightly decreased following the same trend as the height and the volume of bread. The differences were significant (*p* < 0.05). Besides dough stabilization and

gluten network strengthening [26,27], ascorbic acid used in breadmaking contributed to obtaining bread with a larger amount of smaller and evenly distributed pores, a larger volume [28], and a better porosity. Therefore, the addition of Rp provided the dough with a certain amount of ascorbic acid, which determined the increase in bread height, volume, and porosity.

The elasticity of the bread crumb it is property to return to its original shape after the action of a pressing force, and it depends on the quality and quantity of gluten in the flour and the freshness of the product [5]. It was determined a few hours after cooling and is reported as an average of triplicates ± SD (Table 4). Bread crumb elasticity showed a slight decrease for all samples compared to the control (93.3 ± 0.58%), varying from 91.70 ± 0.58% (0.5% Rp) to 88.50 ± 0.50% (2.5% Rp) with significant differences (*p* < 0.05). The decrease of bread crumb elasticity with the increase in the Rp addition could be associated with the slight decrease of gluten content in WF–Rp mixtures, as was discussed before (Section 3.1, Table 1). The crumb elasticity of bread with the AA addition was lower (92.30 ± 0.58%) but close to the control as expected, since its gluten content was equal to that of the control bread.

#### **4. Conclusions**

The substitution of wheat flour with rosehip powder influenced the composition of mixture flours by decreasing the moisture, protein, and wet gluten content, increasing the ash, fibre, and carbohydrate content, and introducing vitamin C into mixture flours at levels reflecting the amount of rosehip powder used. Furthermore, it determined changes in dough farinographic properties and bread physico-chemical characteristics. Compared to the control sample and flour where ascorbic acid was used as an improver, the water absorption of all mixture flours increased due to the increased fibre content. The dough development time, dough stability, and softening degree variations were significant, showing a combined influence of vitamin C provided by the rosehip powder, synthetic ascorbic acid, and the high fibre content in the mixture flours. Moreover, the rosehip powder addition positively influenced the farinographic quality number. The bread prepared from wheat flour with the rosehip powder addition showed a positive evolution of physico-chemical properties, such as a significant increase in height, volume, specific volume, moisture, acidity, and porosity, as well as a slight decrease in elasticity as compared to the control bread. These results indicate that rosehip powder could be used in breadmaking to replace synthetic ascorbic acid.

#### **5. Patents**

The results of the studies were firstly used in a Romanian patent application no. A/0069 of 19.09.2018: Pâine din făină de grâu cu adaos de pudră de măces, e s,i procedeu de obt,inere a acesteia (Bread with rosehip powder addition and process for obtaining the same). The abstract was published in *Buletinul Oficial de Proprietate Industrială*, Sect,iunea Brevete de Invent,ie (*Official Bulletin of Industrial Property*, Patent Section) no. 3/2020, p. 16.

**Author Contributions:** Conceptualization, M.T. and N.V.; Methodology, N.V. and M.T.; Validation, N.V. and M.T.; Formal analysis, N.V.; Investigation, N.V. and M.T.; Writing—original draft preparation, N.V. and M.T.; Writing—review and editing, M.T.; Visualisation, N.V. and M.T.; Supervision, M.T. All authors have read and agreed to the published version of the manuscript.

**Funding:** This research received no external funding. Dunarea de Jos University of Galati funded the APC.

**Acknowledgments:** The authors thank Dizing SRL Brusturi, Neamt County, for technical support. This paper was supported by a grant offered by the Romanian Ministry of Research as Intermediate Body for the Competitiveness Operational Program 2014–2020, call POC/78/1/2/, project number SMIS2014 + 136213, acronym METROFOOD-RO.

**Conflicts of Interest:** The authors declare no conflict of interest.
