Effect of lyophilized jumbo squid (Dosidicus gigas) fin and mantle muscle on dough properties and bread baking performance of commercial wheat flour

Abstract

The effect of 25 and 50 g/kg of lyophilized jumbo squid (Dosidicus gigas) fin (JSF) and mantle muscle (JSM) on dough properties and baking performance of wheat flour were studied. Dough maximum resistance (R _max), extensibility, deformation work (Area, 45-min resting time), baking performance, loaf volume, and acceptability were evaluated. JSF (25 g/kg) almost tripled (P≤ 0.05) R _maxcompared to control dough, while JSF or JSM (50 g/kg) doubled it (P≤ 0.05). As animal protein increased on blend, extensibility decreased (65.6 ± 4.5 for control versus 39.5 ± 1.4 and 26.7 ± 2.0 for 25 and 50 g/kg JSF, respectively). JSF or JSM (25 g/kg) increased (P≤ 0.05) 2.4 and 1.8 times the control area, respectively. Addition of 50 g/kg JSF or JSM significantly affected specific loaf volume decreasing it. Sensory results showed that a low level powder addition (25 g/kg) could be used for bread production.

Se estudió el efecto de 25 y 50 g/kg de aleta (JSF) y músculo de manto (JSM) de calamar gigante (Dosidicus gigas) liofilizado sobre las propiedades de la masa y calidad panadera de una harina de trigo. Se evaluó resistencia máxima (R _max), extensibilidad y deformación por trabajo (Area) a los 45 min de reposo de la masa, calidad panadera (procedimiento de masa directo), volumen de pan (desplazamiento de semillas de colza) y la aceptabilidad del pan. JSF (25 g/kg) casi triplicó (P≤ 0,05) el valor de R _maxcomparándolo con la masa control, mientras que 50 g/kg de JSF o JSM duplicó este valor (P≤ 0,05). A mayor proteína animal en la mezcla, menor extensibilidad (65,6 ± 4,5 para control versus39,5 ± 1,4 y 26,7 ± 2,0 para 25 and 50 g/kg JSF, respectivamente; JSM mostró resultados similares). La adición de 25 g/kg de JSF o JSM incrementó el área (P≤ 0,05) 2,4 y 1,8 veces versusla del control, respectivamente. La adición de 50 g/kg de JSF o JSM afectó de manera significativa el volumen específico de pan (volumen de pan/peso del pan), disminuyendo su valor. El análisis sensorial mostró que la adición de niveles bajos de liofilizado (25 g/kg) pudiera ser utilizada en panificación.

Keywords:

• wheat flour
• jumbo squid
• baking performance
• lyophilized squid muscle

Palabras clave:

• harina de trigo
• calamar gigante
• calidad panadera
• calamar liofilizado

Introduction

The most important functional property of wheat flour proteins is their capacity to form viscoelastic dough when mixed with water. Gluten proteins, such as gliadins and glutenins, are the ones involved in such behavior. The quantity and composition of these proteins are responsible for the dough properties and the baking performance potential of flour (Gupta, Khan, & MacRitchie, 1993; Islas-Rubio, MacRitchie, Gandikota, & Hou, 2005; MacRitchie, 1987). However, it is well known that wheat flour is lysine deficient; thus, incorporation of protein (generally non-muscle proteins) from a different source (i.e., soy flour, nonfat dry milk) is a general practice in order to increase its nutritional value (Alp & Bilgicli, 2008; Roccia, Ribotta, Perez, & Leon, 2009) without affecting the flour properties. Nevertheless, another approach that can be used is the addition of muscle protein such as jumbo squid lyophilized protein.

Jumbo squid (Dosidicus gigasOrbigny, 1835), an endemic species from the pelagic zone of the Eastern Pacific, is the largest and most abundant squid species found from Chile up to the Northwest coast of the United States (Markaida, 2005; Nigmatullin, Nesis, & Arkhipkin, 2001). In Mexico, it is quite abundant in the Gulf of California, representing 95–99% of total jumbo squid captures and approximately 5% of the total national production (CONAPESCA, 2006, Anuario estadístico, http://www.conapesca.sagarpa.gob.mx/wb/cona/anuario_ 2008). Its mantle represents about half of the weight of the edible portion (600–800 g/kg of animal weight; Slabyj, Ramsdell, & True, 1981), while its fins represents about 80 g/kg of animal weight. However, most of its capture is exported to Asian markets with minimum processing and very low value-added. In order to give jumbo squid a better prospective in consumption and therefore in price, there has been an effort to develop value-added products in which jumbo squid could be used.

One of such products, where lyophilized jumbo squid fin (JSF) and mantle muscle (JSM) can be used, are bread loaves fortified with this type of protein. However, the effect of adding jumbo squid protein in wheat flour performance has not been studied. Hence, the objective of the present study was to analyze the effect of adding 25 and 50 g/kg of lyophilized jumbo squid (D. gigas) on the dough properties and bread making performance of commercial wheat flour.

Materials and methods

Raw matter

Squid samples were caught from three different sampling trips between March (samplings S1 and S2) and May 2006 (S3) in two different fishing zones at the Gulf of California. Squid was immediately eviscerated on board and mantle muscle (with fins on) was kept in alternate layers of crushed ice until reaching the Seafood Laboratory at CIAD. Afterwards, interior and exterior skins, as well as pen (gladius), were removed. In order to obtain a dehydrated product with the highest quality to be incorporated to loaf production, the freeze-drying technique was used. Thus, fins were removed from the mantle and both were washed in cold water (<4°C); muscle was cut into 10× 10 cm long pieces, and fins were frozen at −86°C overnight for the freeze-drying process. Sample was always processed within 12 h post capture. Lyophilization of fins and muscle was carried out using a Labconco freeze drier (Labconco Corporation, Kansas City, MO, USA). Freeze-dried sample was powdered by using a food processor eliminating all collagenous fibers left unprocessed. Wheat flour for bread loaf production was bought from a local retailer.

Proximate analysis of freeze-dried raw matter, flour, and bread

Protein (method 46-13) and moisture content (method 44-16) for wheat flour and lyophilized JSF and JSM were analyzed following the procedures of the AACC (1995) and Woyewoda, Shaw, Ke, and Burns (1986), respectively. Protein content was calculated as %N × 5.7 and %N × 6.25 for wheat flour and lyophilized powders, respectively. For bread analysis, protein (method 960.52) and moisture contents (method 44-15A) were analyzed following the procedures of the AOAC (2000) and AACC (1995), respectively. Fat and ash in samples were determined following the AOAC (2000) methodologies (Sec 960.39 and 955.04, respectively). Non-protein nitrogen (NPN) was analyzed following the methodologies recommended by Woyewoda et al. (1986).

Mixograms

The mixograph development time (MDT) of the wheat flour and the blends was determined in duplicate following the method 54-40A of the AACC (1995; including a control + NaCl, 20 g/kg based on flour wt, only for comparison) using a 10-g National Mixograph (National Manufacturing Co., Lincoln, NE, USA). Also, this instrument was used to prepare the dough for the micro-scale physical test. The dough for loaf production, including all ingredients of the recipe, was prepared with a 35-g National Mixograph (National Manufacturing Co., Lincoln, NE, USA).

Physical test on dough

Dough samples were prepared, allowed to rest at 30°C and 900 g/L relative humidity (RH) for 45 min, and evaluated according to Islas-Rubio et al. (2005). Dough maximum resistance to extension (R _max), extensibility (Ext), and deformation work (Area) were measured with the texture analyzer TA-XT2 (SMS/Kieffer rig, Stable Micro Systems Ltd., Godalming, Surrey, England). The analysis was done in duplicate with five to eight measurements per replicate at a test speed of 3.3 mm/s.

Loaf production

Loaf production was carried out following the method 10-10B of the AACC (1995). Briefly, ingredients used were: 35 g of flour or blend (squid at different percentages), 0.84 g of yeast, 4.2 g of sugar, 1.75 g powder milk, 3.5 g of butter, and 0.35 g of salt. The amount of water added varied according to the flour or blend protein content (Mixograph method 54-40A). Percentages of squid used for loaf production were 25 and 50 g/kg (w/w) of either fin (JSF) or mantle muscle (JSM). The dough was rested in a proofing cabinet (model C B7, National Manufacturing Co., Lincoln, NE, USA) at 30°C and 900 g/L RH. Total fermentation time for loaf production was 90 min divided into three stages: the first one after minute 52, the second after minute 77, and the third after minute 90. The dough was put into baking pans and baked for 17 min at 215°C.

Loaf volume

The volumes of bread samples were determined immediately after removing from the oven by the rapeseed displacement method using the pup volumeter (National Manufacturing Co., Lincoln, NE, USA). The bread weight was recorded and the specific loaf volume (SLV) was calculated. The loaves were allowed to cool at room temperature for 1 h; afterwards, loaves were subjectively evaluated.

Consumers’ acceptability

Sixty graduate students and workers from this research center were recruited to evaluate the breads. Age range was between 22 and 54 years, distributed on 24 female and 36 male. The wheat flour bread (control) and the composite breads were randomly numbered and presented to the consumer panel. A hedonic scale from 0 (dislike) to 15 (like a lot; O'Mahony, 1986) was used to point out the degree of acceptance of each product. Even though the number of consumers in the panel was lower than that recommended for a sensory analysis of this type (O'Mahony, 1986), the information collected gives an idea about the product's acceptance.

Statistical analysis

Data were analyzed by a one-way analysis of variance and differences among means were compared using Tukey tests with a level of significance of P≤ 0.05. The SAS software program (SAS Institute, Inc., Cary, NC, USA) was used. At least two replicates were carried out for each analysis (unless otherwise specified).

Results and discussion

Proximate composition of freeze-dried raw matter, flour, and bread

Freeze-dried and powdered fins and mantle muscle from jumbo squid showed a protein content of 932 and 911 g/kg, respectively. This high protein content can be of nutritional as well as functional advantage for loaf production. On the other hand, the protein content in flour, which has been correlated with dough maximum resistance to extension, deformation work, development time, and loaf volume (Islas-Rubio et al., 2005) was of 109 g/kg. This last result is an intermediate protein value, whose overall effect on the physical dough properties would be dictated by the flour protein composition, especially the largest glutenin polymers which are likely to shift the balance of molecular-weight distribution toward stronger dough properties (Southan & MacRitchie, 1999). The flour ash content (5 g/kg) was in the range expected for wheat flour. Bread loaf protein content showed significant differences (P≤ 0.05) when comparing samples with 50 g/kg of JSF or JSM versus control with values of 105.8 ± 3.4 g/kg, 105.1 ± 2.3 g/kg, and 92.8 ± 6.0 g/kg, respectively (Table 1). It has been reported by Cortes-Ruiz, Pacheco-Aguilar, Lugo-Sanchez, Carvallo-Ruiz, and Garcia-Sanchez (2008) that jumbo squid muscle possesses high amounts of NPN; however, even if subtracting this NPN to bread loaf protein content (2.2 ± 1.0 g/kg, 2.3 ± 0.0 g/kg versus 0.8 ± 0.0 g/kg for 50 g/kg JSF, JSM, and control, respectively; Table 1), the protein content of samples with squid muscle remains high which can be an advantage from the nutritional point of view. Conversely, the moisture content of bread made with 25 g/kg and 50 g/kg lyophilized/powdered JSF and JSM presented significant higher (P≤ 0.05) moisture contents than control (308.3–344.1 g/kg, 321.5–340.6 g/kg versus 289.1 g/kg, respectively; Table 1). Lipid content in the bread loaves produced showed no significant differences (P > 0.05), with values ranging around 69.2 ± 20 g/kg (value taken from means of all samples; Table 1).

Table 1. Proximate analysis of bread produced with JSF and JSM.
Tabla 1. Análisis proximal del pan elaborado con aleta (JSF) y músculo (JSM) de calamar gigante.

	Control	JSF (g/kg)		JSM (g/kg)
		25	50	25	50
Moisture	289.1 ± 0.8^a	308.3 ± 3.0^b	344.1 ± 1.4^d	321.5 ± 6.0^c	340.6 ± 2.3^d
Protein	92.8 ± 6.0^a	98.8 ± 1.0^a	105.8 ± 3.4^b	97.8 ± 2.8^a	105.1 ± 2.3^b
Fat	68.7 ± 0.2^a	68.2 ± 2.8^a	66.8 ± 1.0^a	69.7 ± 2.8^a	71.6 ± 0.8^a
Ash	12.2 ± 0.1^a	12.3 ± 0.1^a	12.1 ± 0.1^a	12.2 ± 0.4^a	11.9 ± 0.0^a
NPN	0.8 ± 0.0^a	1.5 ± 0.0^b	2.2 ± 1.0^bc	1.4 ± 0.0^b	2.3 ± 0.0^c
Note: Values are means ± standard deviation (n = 3). Means with different superscript letters in the same row are significantly different (P≤ 0.05). Nota: Los valores son la media ± desviación estándar (n = 3). Medias con letras diferentes en la misma fila son significativamente diferentes (P≤ 0,05).

Physical dough tests and baking performance

The mixograms of wheat flour (control) and their blends are shown in Figure 1[(A)–(F), except (D) which is the mixogram obtained with the control dough with 20 g/kg NaCl added]. Results showed that the MDT and mixing tolerance (bandwidth after the peak) increased with increasing level of JSF [Figure 1(B) and 1(C)] or JSM [Figure 1(E) and 1(F)] in the blends (also see Table 2). This behavior could be due to the higher protein content of the blends, since it has been observed that MDT is influenced primarily, by the flour protein content and secondarily, by the water absorption (Swanson & Johnson, 1943). The dough properties are affected not only by the total amount of protein but also by the protein composition (Lin, Chiang, & Chang, 2003). In the present study, the addition of JSF and JSM during dough production resulted in an increase in resistance to mixing after the maximum (peak), most probably as a consequence of the strengthening of the protein network (Sluimer, 2005) by the animal protein.

Figure 1. Mixograms of wheat flour without (A and D, control, +NaCl 20 g/kg, respectively) and with JSF (B and C) and JSM (E and F).

Figura 1. Mixogramas de la harina de trigo sin (A y D, control, +NaCl 20 g/kg, respectivamente) y con aleta (JSF) (B y C) y músculo (JSM) de calamar gigante (E y F).

Table 2. Dough physical properties and baking performance of wheat flour with JSF and JSM.
Tabla 2. Propiedades físicas y calidad panadera de masa de harina de trigo con aleta (JSF) y músculo (JSM) de calamar gigante.

Dough sample	MDT (min)	R max(g)	Ext (mm)	Area (g/mm)	SLV (cm^3/g)
Control	3.0 ± 0.0^c	40.6 ± 6.3^d	65.6 ± 4.5^a	2,339.4 ± 378.9^c	2.56 ± 0.8^a
JSF 25 g/kg	4.0 ± 0.0^b	119.0 ± 6.4^a	39.5 ± 1.4^b	5,646.4 ± 208.4^a	1.89 ± 0.1^ab
JSF 50 g/kg	4.6 ± 0.1^a	82.4 ± 3.9^bc	26.7 ± 2.0^c	2,479.3 ± 214.8^c	1.56 ± 0.2^b
JSM 25 g/kg	3.9 ± 0.0^b	93.1 ± 2.8^b	36.8 ± 1.0^b	4,196.8 ± 462.3^b	1.84 ± 0.1^ab
JSM 50 g/kg	4.4 ± 0.1^a	76.3 ± 5.4^c	27.6 ± 2.5^c	2,662.1 ± 398.3^c	1.62 ± 0.2^ab
Notes: Values are means ± standard deviation. MDT, mixograph development time; R max, maximum resistance to extension; Ext, extensibility; Area, deformation work; SLV, specific loaf volume. Means with different superscript letters in the same column are significantly different (P≤ 0.05). Notas: Los valores son la media ± desviación estándar. MDT, tiempo de desarrollo del mixógrafo; R max, resistencia máxima a la extensión; Ext, extensibilidad; Area, trabajo de deformación; SLV, volumen específico del pan. Medias con letras diferentes en la misma columna son significativamente diferentes (P≤ 0,05).

Table 2shows the dough properties and baking performance of wheat flour with and without JSF and JSM. Surprisingly, the addition of 25 g/kg JSF tripled R _maxvalue (P≤ 0.05), while the other concentrations and/or protein type doubled the control value (P≤ 0.05; Figure 1). Besides, the addition of 25 g/kg JSF increased (P≤ 0.05) 1.4 times the control value for deformation work or area, while addition of 25 g/kg JSM almost doubled it (P≤ 0.05). Higher animal protein contents did not affect (P > 0.05) this parameter. It is important to mention that stronger dough not necessarily produces a larger bread loaf; a balance between dough strength and extensibility is required. The changes on physical dough properties caused by adding the amounts of animal protein tested in this study did not favor the balance between these important physical parameters as shown by the lower SLVs.

The increase in the area, which is a measure of the energy required for extension and taken as a measure of flour strength (Hoseney, 1994), indicated a strengthening effect caused by the addition of 25 g/kg animal protein. It is possible that, during mixing and kneading, formation of more interchain disulfide bonds was promoted, thus increasing the average molecular weight of the proteins and the dough strength (Wrigley, Békés, & Bushuk, 2005). It is well known that glutenin and gliadin possess a relatively large amount of disulfide bonds that could be mobilized through disulfide interchange reactions (Goldstein, 1957; Kaczkowski & Mieleszko, 1980). These interchange reactions require “mobile” (soluble or low-molecular-weight) sulfhydryl-containing substances to initiate the series of disulfide interchanges (Bloksma & Bushuk, 1988). Myosin, a molecule that possesses 40 sulfhydryl groups with no disulfide bonds (Xiong, 1997), can be a precursor of these interchanges.

The addition of JSF or JSM to dough impaired the balance of gluten proteins on samples tested (Table 2), affecting (P > 0.05, except for 50 g/kg JSF) the SLV (effect also observed in Figure 2) and extensibility of the dough (P≤ 0.05). This last parameter was more affected (P≤ 0.05) as the animal protein increased on the dough matrix. Similar results were found by Roccia et al. (2009) when tested the influence of soy protein on rheological properties of wheat flour, finding an increment in the extension area up to a certain ratio of soy protein substitution. The balance of dough strength and extensibility are believed to be the most important factors governing the suitability of a flour to make good bread (Bushuk & Békés, 2002). The dough needs to have the properties that enable it to stretch in response to gas expansion (extensibility), but strength should be appropriate to allow bubble expansion, while preventing the collapse of cell walls (Cornish, Békés, Eagles, & Payne, 2006). In the present study, crumb subjective evaluation showed that addition of animal protein to wheat flour, up to 50 g/kg, did not affect much the bread-crumb grain of the loaves (Figure 2).

Figure 2. Bread-crumb grain (top) and loaves obtained from the wheat flour without (control) and with JSF and JSM.

Figura 2. Estructura de la miga (arriba) y panes obtenidos de la harina de trigo sin (control) y con aleta (JSF) y músculo (JSM) de calamar gigante.

Consumers’ acceptability

In order to find out the acceptance of this type of product, a sensory analysis was carried out on all samples (Table 3). The analysis showed that loaves with lower squid content (25 g/kg fin or mantle muscle) had similar acceptability than control (10.81 versus 9.12 and 9.32 for control, JSF, and JSM, respectively). On the contrary, loaves with higher squid content (50 g/kg fin or muscle) were the most affected by the scores attaining values of 6.73 and 7.64, respectively. Thus, the acceptability of this type of bread indicates that addition of 25 g/kg JSF or JSM can be an option to develop a value-added product. This last result deserves a comment; the higher acceptability in lower squid content samples is most probably due to loaves having a similar flavor than control, while loaves with higher squid content presented a “fishy” flavor, meaning that if a customer cares for this type of flavor, most probably the one with higher squid protein would be the most accepted type of bread.

Table 3. Consumers’ acceptability of bread produced with JSF and JSM.
Tabla 3. Aceptabilidad por el consumidor del pan elaborado con aleta (JSF) y músculo (JSM) de calamar gigante.

Samples	Acceptability
Control	10.81^a
JSF 25 g/kg	9.12^a
JSF 50 g/kg	6.73^c
JSM 25 g/kg	9.32^a
JSM 50 g/kg	7.64^b
Notes: Acceptability test used a hedonic scale from 0 (dislike) to 15 (like a lot). Means with different superscript letters are significantly different (P≤ 0.05).Notas: La prueba de aceptabilidad utilizó una escala hedónica de 0 (me disgusta) a 15 (me gusta mucho). Medias con letras diferentes son significativamente diferentes (P≤ 0,05).

Conclusions

Results from the present study demonstrate that lyophilized and powdered jumbo squid, either from fin or mantle, can be used in the production of a value-added product, such as bread loaves. However, results also indicate that low concentration, 25 g/kg of lyophilized product, is recommended as they were the least affected and most accepted by the sensorial panel.

Acknowledgment

The authors wish to thank Fundación PRODUCE Sonora of the Republic of Mexico for its support for the realization of this study under project # 26-2007-1152.