A ANOVA três fatores foi utilizada para avaliar se houve interação entre os fatores para cada variável resposta. A ANOVA um fator foi utilizada para verificar se houve diferença entre as médias de cada tratamento, com teste post hoc de comparação múltipla de Tukey. O teste t pareado foi utilizado para verificar se houve diferença significativa entre as etapas (após o cozimento e após o descongelamento). Valores de p < 0,05 foram considerados estatisticamente significativos. As análises estatísticas foram realizadas com o auxílio do programa SPSS versão 20.0 para Windows (SPSS Inc., Chicago, III, USA).
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6 ARTIGO PRODUZIDO
6.1 O artigo intitulado “Effect of cooking associated to phosphate additive in yield and physical-chemical quality of peeled Pacific white shrimp (Litopenaeus vannamei)” foi submetido para publicação no periódico “LWT- Food Science and Technology”, que possui fator de impacto 2.711 e Qualis A2 da CAPES para área de Nutrição.
36
Elsevier Editorial System(tm) for LWT - Food Science and Technology Manuscript Draft
Manuscript Number: LWT-S-17-10097
Title: Effect of cooking associated to phosphate additive in yield and physical-chemical quality of peeled Pacific white shrimp (Litopenaeus vannamei).
Article Type: Research paper
Keywords: quality; crustaceans; additive; phosphate.
Corresponding Author: Dr. Alex Augusto Augusto Goncalves, Ph.D
Corresponding Author's Institution: Federal Rural University of Semi-Arid First Author: Micaela da Silva Paula Damasceno, MSc
Order of Authors: Micaela da Silva Paula Damasceno, MSc; Alex Augusto Augusto Goncalves, Ph.D
Abstract: The evaluation of the association of the food grade additive phosphate (sodium tripolyphosphate - STPP and blend CARNAL® 961) used as a pre-treatment to the industrial cooking process of the peeled shrimp was carried out. The effects of phosphate concentration (3 and 5% w:v) and contact time (30 and 60 min) on the yield (weight gain and loss) and the shrimp physical-chemical quality were evaluated. Samples immersed in water (30 and 60 min) were considered as controls. The water holding capacity, moisture, protein, phosphate, sodium texture, color and pH analyzes were performed. Food grade phosphates showed a satisfactory effect in the weight loss reducing and the water holding capacity increasing, despite the 5% STPP and 5% Blend treatments (60 min) promoted the phosphate residual above to the international limit allowed (1%) and the latter treatment also had a pH above that allowed in Brazil (7,85). The phosphate uses before cooking step in shrimp plant processing improve the product quality, since that it is in accordance with the current legislation that governs each country. Suggested Reviewers:
Robiel K Moawad PhD
Researcher, Food Science and Technology Department, National Research Centre, Egypt
rk_moawad@hotmail.com
He has worked with food additives (phosphate) on drip loss evaluation. Berna Kilinc PhD
Researcher, Fishery and Fish Processing Technology, Ege University, Turkey
kilinc@mail.ege.edu.tr
She has worked with phosphate treatment on the quality of frozen-thawed fish species
Maria Leonor Nunes PhD
Researcher, IPIMAR mlnunes@ipimar.pt
37
Effect of cooking associated to phosphate additive in yield and physical- chemical quality of peeled Pacific white shrimp (Litopenaeus vannamei).
Micaela da Silva Paula Damasceno1and Alex Augusto Gonçalves1,21
1Postgraduate Program in Nutrition (PPGNUT), Health Sciences Center (CCS), Federal University of
Rio Grande do Norte (UFRN), Natal, RN, Brazil. 2Laboratory of Seafood Technology and Quality
Control (LAPESC), Animal Sciences Department (DCA), Agricultural Sciences Center (CCA), Federal Rural University of Semi-Arid (UFERSA), Mossoró, RN, Brazil.
Abstract
The evaluation of the association of the food grade additive phosphate (sodium tripolyphosphate - STPP and blend CARNAL® 961) used as a pre-treatment to the industrial cooking process of the peeled shrimp was carried out. The effects of phosphate concentration (3 and 5% w:v) and contact time (30 and 60 min) on the yield (weight gain and loss) and the shrimp physical-chemical quality were evaluated. Samples immersed in cold distilled water (30 and 60 min) were considered as controls. The water holding capacity, moisture, protein, phosphate, sodium texture, color and pH analyzes were performed. Food grade phosphates showed a satisfactory effect in the weight loss reducing and the water holding capacity increasing, despite the 5% STPP and 5% Blend treatments (60 min) promoted the phosphate residual above to the international limit allowed (1%) and the latter treatment also had a pH above that allowed in Brazil (7,85). The phosphate uses before cooking step in shrimp plant processing improve the product quality, since that it is in accordance with the current legislation that governs each country.
Keywords: quality; crustaceans; additive; phosphate.
1Corresponding author: Alex Augusto Gonçalves, Chief of Laboratory of Seafood Technology and Quality Control (LAPESC), Animal Sciences
Department, Agricultural Sciences Center (CCA), Federal University of Semi-Arid (UFERSA), Av. Francisco Mota, 572, Costa e Silva, 59625-900, Mossoró, RN, Brazil, Tel: + 55 84 33178300 r 1419 | Fax: + 55 84 33178361 | Mobile: + 55 84 991713135, E-mail: alaugo@gmail.com
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1. INTRODUCTION
Shrimp is one of the most traded, consumed and valued aquatic food products on the
world market (Chen, Deng, and Li, 2013) and therefore, the estimated global shrimp
production growth rate for the period 2015 to 2018 is expected to reach the value of
4.2%, and in this perspective, the Pacific white shrimp L. vannamei continues being
the species with the highest quantitative impact (Anderson, Valderrama and Jory,
2016). Its consumption is recommended for the general population because it is a
product of high nutritional quality, mainly because it is a source of nutrients for
human consumption, such as proteins and lipids (Rosa and Nunes, 2004).
Cooked shrimp represent 16% of shrimp products marketed worldwide (Anderson et
al., 2016), and the cooking process adds value to shrimp and is beneficial for the
inactivation of some enzymes associated with loss of quality and destruction of
undesirable microorganisms (Niamnuy, Devahastin, and Soponronnarit, 2007;
Martínez-Alvarez, López-Caballero, Gómez-Guillén, and Montero, 2009). However,
the application of heat may also influence the protein denaturation, resulting in loss of
water holding capacity (WHC) and moisture content, which can be correlated with the
increase in shrimp meat stiffness and weight loss (yield) (Hughes, Oiseth, Purslow,
and Warner, 2014; Wachirasiri et al., 2016).
In this sense, phosphate additive has been highlighted in the scientific literature as a
potential alternative as a humectant agent (Chantarasuwan, Benjakul, and
Visessanguan, 2011). The use of phosphates in different seafood species has
demonstrated that its use is valid to avoid large yield losses (Gonçalves et al., 2008;
Gonçalves and Ribeiro, 2008a, 2008b, 2009; Kin at al., 2009; Carneiro et al., 2013a;
2013b; Nguyen et al., 2013; Wangtueai et al., 2014). Regardless of the seafood
species, the amount of phosphate used should be only that necessary to produce the
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use may constitute economic fraud, besides leading to sensorial losses (Gonçalves
and Ribeiro, 2008a; Chao et al., 2016; Torti et al., 2016).
The phosphates are worldwide used in the seafood industry and are legally allowed,
subject to certain conditions of use and maximum limits that may vary from one
country to another (European Parliament and Council, 2011). In Brazil, phosphates
can be added as stabilizers only in the external coating (glazing) of frozen seafood
(Brazil, 1988; Brazil, 2017a). Therefore, the development of new research should be
encouraged to demonstrate the technical, economic and safety feasibility of using the
food grade additive phosphate in seafood products.
Based on this information, the objective of this study was to evaluate the association
of the use of the food grade additive phosphate (at different concentrations and
contact time) as a pre-treatment to the cooking process of the peeled Pacific white
shrimp Litopenaeus vannamei, in the yield (weight gain and loss) and in the physical-
chemical quality.
2. MATERIAL AND METHODS 2.1 Raw materials and additives
The shrimp Litopenaeus vannamei (average weight of 7g) was obtained from a
shrimp processing plant (Aracati, Ceará, Brazil), previously peeled, kept on ice (ratio
1: 2, shrimp: ice), and then separated in 1000g (285 parts/kg, average weight of 3.5g
per unit) for each experimental treatment.
Food grade sodium tripolyphosphate (STPP, Synth, Brazil) and phosphate blend
CARNAL® 961 (combination of Tetrasodium diphosphate, Tetrapotassium
diphosphate, Pentasodium triphosphate, and Pentapotassium triphosphate,
Chemische Fabrik Budenheim KG, Germany) were individually dissolved in cold
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2.2. Experimental design
The experimental design was based on the best results obtained from Gonçalves
and Ribeiro (2008b) study, using a 2 x 2 x 2 factorial experiment (type of additive,
additive concentration and contact time) obtaining the follow experimental groups:
3% STPP for 30 min; 3% STPP for 60 min; 5% STPP for 30 min; 5% STPP for 60
min; 3% Blend for 30 min; 3% Blend for 60 min; 5% Blend for 30 min; and 5% Blend
for 60 min. Control group: samples were immersed in cold distilled water (30 and 60
min).
The shrimp samples were immersed in each experimental solution with periodic
agitation (each 10 min), followed by drainage (5 min) and steam cooking (100°C for 2
min) in a horizontal continuous cooker (Brusinox model 010567/2004), following the
technological process (time and temperature) used by the industry. After cooking,
samples were cooled (1 min - cold water, 2±1°C) and drained (5 min under
refrigeration, 4±1°C). Afterwards, were packed in polyethylene bags, sealed,
identified, stored in isothermal boxes with flake ice (1:1) and transported to the
Laboratory of Technology and Quality Control of Fish (LAPESC, UFERSA), in
Mossoró, RN, Brazil. The time between sample preparation and transport did not
exceed 2 hours.
Part of the samples from each experimental group were separated for the first
laboratory analysis (after cooking, AC), and another one was conducted to freezing
process (Ultra freezer Indrel CPH45D) at -35°C, and kept for 15 days. After this
period, samples were thawed at 5°C (Vertical Exposure Refrigerator 578 L) for 18
hours, drained for 5 minutes, and submitted to laboratory analysis (after thawing,
AT). The methodological procedures (presented in Figure 1) were followed according
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2.3 Yield evaluation
The gain or loss of weight and subsequent yield calculation was determined by
weighing samples in the following steps: raw shrimp, after immersion, after cooking
and after thawing. The yield calculation was determined according to Gonçalves and
Ribeiro (2008b) and Rattanasatheirn et al. (2008), being expressed as Yield (%) =
[(Pf – Pi)/Pi] x 100 where Pi being the initial sample weight (g) and Pf the final sample
weight after drainage (g).
2.4 Physical analyzes (pH, color, texture, and water holding capacity)
The hydrogen ionic potential (pH) was evaluated using a digital pHmeter (HANNA©)
with a calibrated electrode, which was inserted directly into the sample for reading.
The color measurement was evaluated at three different points in the same sample
using a colorimeter (CIE System L* a* b*, model CR-400), whose system considers
the coordinates L* luminosity (black/white), a* red (green/red) and b* yellow
(blue/yellow). The apparatus was calibrated before reading the samples using a
white standard. The texture was analyzed using a shear force (SF) parameter
measured by a Texture Analyzer (TA-XT-125), coupled to the Warner-Bratzler device
(HDP/WBV). The results were expressed in kgf/cm2 (kilogram-force per square
centimeters), obtained by the means of maximum force of rupture, in the direction
perpendicular to the axis of the muscular fibers, in the second segment of the shrimp.
The thickness of the sample for the cut was dictated according to the thickness of the
shrimp. For each triplicate, the mean maximum breaking strength between two
shrimp units was used. The water holding capacity (WHC) was determined by the
pressure method with filter paper (Hamm, 1960), using the following formula: WHC
(%) = 100 - [(Pi - Pf)/Pi] x 100, where Pi is the initial sample weight (~0.5 g) and Pf is
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2.5 Chemical analysis (moisture, protein, M/P ratio, phosphate, and sodium)
The water (moisture) and protein contents were analyzed through the Near Infrared
Spectroscopy (NIRS) spectrophotometer (model 2400-RTW), with an interval of
1200-2400 nm in steps of 1 nm previously tested. The moisture and protein results
were used for the mathematical calculation of the moisture/protein (M/P) ratio. The
phosphate content was determined by the methodology of the Adolfo Lutz Institute
(IAL, 2008). This analysis is based on the principle that an acidic reaction of
orthophosphate with vanadium ammonium molybdate solution (vanadum
phosphomolybdate) forms a yellow complex capable of being measured
colorimetrically by a spectrophotometer, making it possible to estimate the total
phosphorus (P) content and its equivalence in phosphate (g P2O5/100g). The sodium
content was determined using the flame atomic emission spectrophotometer (AOAC,
2005). Flame photometry analysis is based on the principle of atomic spectroscopy,
where a sample containing metal cations is inserted into the stoichiometric flame and
analyzed by the amount of radiation emitted by excited atomic or ionic species.
2.6 Statistical analysis
The three-way ANOVA was used to assess whether there was an interaction
between the factors for each response variable. One-way ANOVA was used to verify
if there was the difference between means of each treatment, with post-hoc Tukey
multiple comparison tests. The paired t-test was used to verify if there was a
significant difference between the steps. Values of p<0.05 were considered
statistically significant. Statistical analyses were performed using the SPSS software
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3. RESULTS AND DISCUSSION
3.1 Effect of interaction between factors for each response variable
The effect of significant interaction between the three factors is presented in Table 1
and was identified only after cooking (AC) for the variables yield loss (%) (p = 0,000),
WHC (%) (p = 0,001) and b* value (p = 0,043); only after thawing (AT) to the variable
protein (g/100g) (p = 0,028); and in both steps (AC and AT) measurements for
moisture (g/100g) (AC, p = 0,026; AT, p = 0,004), M/P ratio (AC, p = 0,010; AT, p =
0,014) and L* value (AC, p = 0,014; AT, p = 0,003). The variables phosphate (g
P2O5/100g) (p = 0,000) and sodium (mg Na/100g) (p = 0,000) also presented a
statistically significant triple interaction.
3.2 Weight (g) variation during the shrimp processing steps and yield loss (%) after cooking and after thawing
The samples behavior regarding the weight variation during the processing steps
was verified through the weight gain after the immersion for all treated samples,
weight loss after cooking and after thawing, as shown in Figure 2. It can be clearly
seen that the food grade additive phosphate proved to be effective in water retention
after immersion, and especially after cooking and thawing. It has further been shown
that the increase in the additives concentration and the time of exposure are also
correlated with the decrease in weight loss after cooking and thawing. These results
corroborate studies already carried out with the phosphate and blends application as
pre-treatment to the cooking or freezing of several seafood species (Gonçalves et al.,
2008; Gonçalves and Ribeiro, 2008a; 2008b; 2009; Kin at al., 2009; Carneiro et al.,
2013a; 2013b; Nguyen et al., 2013; Wangtueai et al., 2014).
In Table 2, the results of the response variables for the control samples (30 and 60
44
concentrations (3 and 5%) and two contact times (30 and 60 min) are presented. The
physicochemical analysis was performed after cooking and after thawing.
The results of the variable weight loss (% yield) showed that the control samples had
the highest losses (AC and AT). The lowest losses were observed in the treatments
with 5% Blend - 60 min (AC) and 5% STPP - 60 min (AC), as well as in all samples
treated with Blend (AT). The weight loss after cooking and after thawing has shown
that the use of the phosphate additive does not increase the weight (g) of the
product, it only reduces its loss. The present results corroborate with other studies
verifying that different types and concentrations of the phosphate results in higher
yield values than in untreated samples (Gonçalves et al., 2008; Gonçalves and
Ribeiro, 2009; Kin et al., 2009; Wangtueai et al., 2014; Omar et al., 2016).
Gonçalves et al. (2008) found that phosphate blend solutions promote higher yield
than the use of phosphate alone (STPP) in four different seafood species. This may
occur, according to Gonçalves and Ribeiro (2008a), due to the composition of the
phosphate mixture that increases the efficacy of the additive on increasing WHC and
subsequent yield. Omar et al. (2016) also verified that the longer the contact
(exposure) time and the phosphate concentration, the lower the weight loss in
shrimp, a result similar to that found in the present study.
Considering the effect “after cooking” and “after thawing” in the variable yield loss, the results showed a significant difference (p<0.05), except for the 3% Blend (30 min)
and 5% Blend (30 min) treatments. After cooking, the samples showed the highest
yield losses, except for 5% Blend (60 min), that the greatest loss was observed after
thawing. It should be noted that heat treatment may result in product yield losses,
and that may lead to harmful economic consequences for the industry, but this and
45
these losses (Gonçalves et al., 2008; Gonçalves and Ribeiro, 2009; Kin et al., 2009;
Wangtueai et al., 2014).
Based on these results, it can be assumed that for the industry the use of 5% Blend
(60 min) is more advantageous since it reduces in greater proportions the yield loss
(AC and AT) with the better result after cooking. In contrast, for the consumer who
performs the thawing step after product acquisition, the use of 5% STPP (60 min)
was as satisfactory as all samples treated with Blend. It is important to consider that
the isolated use of phosphate, as STPP, besides being able to perform most of the
functions of the phosphate blends, its cost is less onerous and can also be
considered beneficial for the industry (Gonçalves, 2012). Therefore, the choice of the
type of phosphate to be used requires an effective evaluation of all the factors
involved to validate the viability of its use and its technological effect on the seafood.
3.3 WHC, Moisture, Protein, M/P ratio and Texture
Considering that the seafood is a perishable food, water is an important element in its
composition in different aspects (Hughes et al., 2014). The ability of the meat to
retain its own water in the face of a force application such as cutting, heating,
grinding and pressing is called water holding capacity (WHC) (Niamnuy et al., 2008;
Hugues et al., 2014). In the present study, WHC demonstrates that the control
samples had the lowest WHC in both steps (AC and AT, Table 2). According to
Hugues et al. (2014), the lower WHC can negatively affect the appearance of the
meat, and this may influence the consumer's willingness to buy the product. As an
alternative, the phosphate has been indicated for the increase of WHC in cooked
shrimp, contributing to the improvement of the sensorial properties of the final
product and an increase in consumer preference (Gonçalves et al., 2008; Gonçalves
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Although the treatments with 3% and 5% STPP (30 min) also presented lower WHC
(AT), in general, the use of the phosphate resulted in higher WHC values, with
emphasis on the samples treated with 5% Blend (30 min, AC) and 5% Blend (60 min,
AC and AT). It is known that the efficacy of phosphates in the water retention
properties of meat products depends on the type and amount of additive for the
particular food product (Lopkulkiaert, Prapatsornwattana, and Rungsardthong, 2009).
There was a significant difference (p<0.05) for some of the steps (AC or AT), except
for the treatment with 5% Blend (30 min), where the highest WHC values were
observed after cooking. The ability of the muscle to absorb water during processing
and WHC after cooking and after thawing are important factors governing the
seafood quality and its products (Chantarasuwan et al., 2011).
Proteins can be considered the second main component of seafood and their
integrity is closely associated with the performance of their functional properties
(Chantarasuwan et al., 2011). For physiological reasons, there is a strong
relationship between moisture and protein in the meat, including seafood (De Greef,
Verstegen, and Kemp, 1992; Yeannes and Almandos, 2003; Breck, 2014). The
highest M/P ratio was observed in the samples with higher moisture and lower
protein quantitative (Table 2), with the 5% Blend treatment (60 min) being the highest
expression of the studied variables and the control treatment (Water - 30 min) the
lowest M/P ratio. The difference between AC and AT for these variables showed a
higher M/P ratio after cooking, i.e. despite the loss of water in the cooking stage, the
step after thawing presented higher loss of this element with higher protein
concentration. These results behave similarly to the WHC results already mentioned.
Van Ruth et al. (2014) verified an average on M/P ratio in chilled shrimp (4.8) and in
frozen shrimp (7.2). These samples were purchased in several retail establishments,
47
cooked or if treated with additives. In the present study, the M/P ratio was well below,
with a higher value (4.41) in the 3% Blend treatment (60 min, AC). In addition, the
present results differ from those found by Van Ruth et al. (2014) in another aspect,
because the authors concluded that, independently of the seafood species, the
frozen samples present a higher M/P ratio than the chilled samples. Possibly, the
divergence exists because in the present study all samples were submitted to the
cooking process and the structures and mechanisms that influence the moisture and
protein functionality after cooking are different from those of the raw meat, being able
to behave even in the opposite way.
The change in shrimp texture is a factor that requires attention in processing since it
is easily perceived by the consumer and may negatively affect the quality of the
product (Martínez-Alvarez et al., 2009). The effects of boiling conditions on texture
changes are similar to changes in proteins (Niamnuy, Kerdpiboon, and Devahastin,