Consumers ’ preference and perception of smoke-dried white shrimp ( Nematopalaemon hastatus ) in coastal areas of Ondo State , Nigeria

The study assessed consumers’ preference and perception of smoke-dried white shrimps in Igbokoda, a coastal area of Ondo State, Nigeria. The community was purposively chosen because the town is a major cluster for natives from coastal communities in Ilaje and Ese-Odo LGAs of Ondo State, Nigeria. Forty shrimp consumers (20 males and 20 females) were randomly selected for this study. They assessed the sensory properties of smoke-dried shrimps collected from processing units in Ayetoro and Bijimi. The two communities were purposively chosen for the predominance of white shrimp processing using smoking method. Five smoke-dried samples (A1-A5 and B1-B5) were collected from Ayetoro and Bijimi respectively. Panelists assessed the sensory attributes of white shrimps using a 9point hedonic scale. Results indicated that there were significant differences (p ≤ 0.05) in the organoleptic properties of the white shrimps. Samples A3, B2 and B3 had low acceptability while samples A1 and B5 were more accepted than the other samples. Taste of the samples was the highest significant factor that influenced general acceptability among assessors as indicated by the magnitude of its t-Stat. All the sensory attributes were positively correlated (R = 0.71) with general acceptability and 50% (R2 = 0.50) dependent on these sensory attributes. Majority of the respondents said they consumed white shrimps with no allergic reactions in dried form. Consumers were highly satisfied with smoked white shrimps in market places; however, off flavour, inadequate taste, odd appearance and the quantity of by-catches were the perceived reasons that determined consumers’ satisfaction with shrimps in the market outlets. Hence, more emphasis should be laid on reducing off flavour, odd appearance, by-catches and increased utilization of white shrimp in food products. This would further increase consumers’ satisfaction, patronage in market places, boost coastal economy and contribute to healthy living of consumers in Nigeria.

. Apart from their delicacy, they contain amino-acids, peptides, protein and other useful nutrients such as calcium and vitamins (Bello, 2013).Seafood in its different forms contributes substantially to the diet of Nigerians (Ajala and Oyategbe, 2013).White shrimp (Nematopalaemon hastatus) (Aurivillius, 1898) also known as estuarine prawn is one of the most important animal sources of food for a healthy diet.Its consumption represents 28% of the total consumption of animal protein content of the average Nigerian diet (Food and Agricultural Organization, 2012).They are abundant and shrimped in the over 180 km coastline in coastal areas of Ondo State, Nigeria with an estimated 75% frequency of occurrence in shrimp catches (Olawusi and Ajibare, 2014).Thus, the species is of utmost importance in the diets of coastal inhabitants and beyond while activities in the shrimp value chain serves as source of employment and raw materials for food processing and allied industries (Bello, 2013).White shrimps are mostly sold in dried form in Nigeria; they are milled and used in flavoring different types of food.In other climes, most especially European countries, they are generally consumed fresh (FAO, 2012).Its consumption in Nigeria varies between the coastal and inland regions; they are marketed within and outside the study area with consumers geographically distributed across the country; most especially in the Southern States (Bello, 2013).
Despite the nutritional benefit of this aqua food, age, education, marital status, income, family size, residing area, occupation, religion, food attribute (sanitation, nutrition, package, quality, price and sensory properties, etc.) and awareness on nutritional properties are some of the few factors that affect its consumption (Balfour et al., 2014).Pieniak et al. (2011) stated that shrimp consumption, frequency of consumption, and preferences are affected by consumers' geographic, social and cultural characteristics.Food preferences are also affected by a number of sensory (taste, smell, texture etc) and non-sensory factors (behaviour, beliefs, personal characteristics, risk perception, etc) (Honkanen et al., 2006).
Generally, toxic substances, handling and processing methods are some of the factors that can affect these attributes.Therefore, an estimate of freshness of this product can be obtained by defining criteria related to changes in sensory attributes such as appearance, odour, colour and texture that can be measured or quantified by sensory or instrumental methods (Olafsdottir et al., 2004).Huidobro et al. (2002) reported that the market value of shrimp is predominately based on the visual appearance of their body colour; thus appearance and the resulting quality implications play a significant role in maintaining a high consumer acceptance and perception.Consumers' perception of seafoods provides information on specific experiences (e.g., familiarity with shrimp preparation, eating frequency) which may influence subjective knowledge about shrimp (Jodice et al., 2006).Other factors such as seasonality, consumer's income, storage, distance between the consumers and markets, product attributes, processing method, quantity of bycatches and awareness affect the perception of an aqua product.The advantage of product awareness cannot be overemphasized, assisting various sectors (processing, marketing, and economic) to improve the knowledge of consumers towards the nutritional benefits of N. hastatus (Huidobro et al., 2002).
Various researchers have reported different findings on shrimps in Nigeria.These findings include researches on smoke-curing of shrimp (Adeparusi et al., 2003); biology (Animoro and Meye, 2007); species richness, abundance, condition factor and length-weight relationship (Olawusi and Ajibare, 2014); Olawusi-Peters et al. 2014) and indigenous knowledge of the species (Okayi et al., 2013).In all these studies, there is relatively little/no information on the preference and perception of smoke-dried white shrimp particularly among consumers in coastal areas of Ondo State, Nigeria.Therefore, the objectives of the present paper include (i) obtaining information on the sensory properties of smoke-dried shrimps (ii) evaluating the relationship between the sensory attributes and general acceptability of the shrimps (iii) evaluating shrimp consumption level and frequency (iv) assessing consumers perception of the white shrimps in the study area.By analysing this information, it is possible to prepare a strategic plan which can influence processing and marketing decisions and ascertain long term goals of the shrimp fishery as well as contribute to nutrition policies at both regional and national scales.

Study area
The study was carried out in the coastal area of Ondo State, Nigeria.The study area is at the extreme southern part of Ondo State.The coastal areas of Ondo State consist of over five hundred settlements spreading over 3,000 km 2 .The area has over 180 km long shoreline thereby making it the longest coastline in Nigeria (Bayode et al., 2011).The study area falls within Latitude 6° 21' 00'' N and Longitude 4° 48' 00'' East of the Greenwich Meridian (Figure 1).

Sampling methods
White shrimp consumers were identified in Igbokoda.The community was purposively chosen for this study because the town is a major cluster for natives from coastal communities in Ilaje and Ese-Odo LGAs that makes up the coastal areas of the State.Forty (40) shrimp consumers comprising of 20 males and 20 females were randomly selected for this study.The selected consumers equally assessed the sensory properties of smoke-dried shrimp samples collected from Ayetoro and Bijimi; chosen for the predominance of white shrimp processing using smoking method.Five (5) samples (A1-A5 and B1-B5) were collected from processors in the two communities respectively.Samples were produced by sorting out by-catches and spreading measured quantity on a mat; then smoke-dried between 5 and 7 h depending on heat intensity and dryness of the wood (Rhizophora racemosa) commonly used (Centre for Environment Human Right and Development, 2007;Alhaji et al., 2015).Panelists assessed the sensory attributes of the samples using a 9-point hedonic scale: (extremely (9), very much (8), like moderately (7), like slightly (6), neither like nor dislike (5), dislike slightly (4), dislike moderately (3), dislike very much (2), and dislike extremely (1).Sensory attributes rated in the samples were colour, taste, flavour, crispness, appearance and overall acceptability.Structured questionnaire was used to assess consumers' information on preference and perception of white shrimps in the study area between December, 2016 and January, 2017.

Statistical analysis
Descriptive statistical tools such as tables, charts and percentages were used to describe consumers' information.Sensory attributes of smoke-dried white shrimps were subjected to one way analysis of variance using the Statistical Package for Social Science (SPSS) Version 20.0.Means were separated where significant difference occurs at p ≤ 0.05 using the Duncan's New Multiple Range Test (DNMRT).Multiple regression analysis was used to evaluate the effects of sensory attributes on the acceptability of white shrimps in the study area.

Demographic characteristics of selected white shrimp consumers in the study area
Figure 2 provides information on the distribution of white shrimp consumers by demographic characteristics.It reveals that 22.5% of the respondents were below 20 years of age; 25% were between ages 20 and 29; 30% fell between 30 and 39 years old, 12.5% were between 40 and 49 years while 10% of the selected white shrimp consumers were above 49 years.Results further indicated that 7. 5, 10, 12.5, 20, 17, 5 and 12.5% were natives of Arogbo, Awoye, Ayetoro, Igbokoda, Mese and  Ondo respectively.Fifty percent (each) of the consumers were male and female respectively.Only five percent of the consumers had no formal education, 25% had primary education, 50% had secondary while 20% had tertiary education.Equally, 25% of the consumers were students, 15% were civil servants, 13% were traders, and 23% were artisans while 25% were unemployed.

Sensory analysis of smoke-dried white shrimp
Results of the differences in the sensory attributes of dried white shrimps collected from Ayetoro and Bijimi is presented in Table 1 while the effect of the sensory attributes on the general acceptability of smoke-dried shrimps is presented in table 2. Colour of smoked N.  Results further indicated that all the sensory parameters had positive and significant (p ≤ 0.05) influence on the general acceptability of the product going by their pvalues, t-Stat and positive coefficients (Table 2).Taste of the shrimps was the highest significant factor that determined the general acceptability of panelists as indicated by the magnitude of its t-Stat.This was followed by appearance, flavour, colour and crispness.All the sensory attributes were positively correlated (R = 0.71) with general acceptability and 50% dependent on the attributes.

Consumption Trend among Selected Consumer
Table 3 provides information on the descriptive statistics of the consumption trend of white shrimps among selected consumers.It indicates that 22.5% of the respondents consumed shrimp daily, 45% consumed it weekly, 5% consumed it monthly while 22.5% took it occasionally.Twenty percent of the respondents consumed it in fresh form while the majority (80%) of them preferred it in dried form.Only 15% of the consumers said they were allergic to white shrimp consumption while 85% said they showed no allergy to it.

Accessibility and satisfaction
Consumers' information on accessibility and satisfaction of smoke-dried N. hastatus in the study area is presented in table 4. It reveals that 50% of the consumers purchased dried shrimps from retail outlets, 12.5% got it from wholesalers while 37.5% bought it from processors.The largest proportion (70%) of the consumers said that dried shrimps were readily available in marketing outlets, 25% said they were seasonally available while 5% said they were less available.Equally, 92.5% said seasonality affects the availability of the product in market outlets while 7.5% said availability was not affected by season.Seventy-five percent said white shrimps were more available in the raining season and 25% believed they are less available in the dry season.Also, 45% of the respondents perceived smoke-dried N. hastatus as an expensive aqua product; 50% said they were less expensive while 5% said it was not expensive seafood.Results further indicated that over half (55%) of the consumers said they were highly satisfied with smoke-dried shrimps in different marketing outlets, 42.5% said they were less satisfied while only one respondent (2.5%) was not satisfied.Results further show that 22.5% and 52.5% said odd appearance and quantity of by-catch were the reasons for their non-satisfaction with shrimps in market places respectively.Majority (77.5%) of the consumers bought dried shrimp from marketing outlets

Acceptability and types of food flavoured with dried N. hastatus
Consumers' acceptability and type of food flavoured with dried N. hastatus is presented in Figure 3.It indicates that 62.5% of the consumers highly accepted food flavoured with white shrimps; 12.5% said food flavoured with dried white shrimp were less acceptable while 32.5% said such food was moderately acceptable.Furthermore, 32.5% said they appreciate stew flavoured with dried shrimps, 27.5% liked it in soup, 15% in vegetables, 12.5% in beans cake (moi-moi) and 12.5% in all types of food.

Utilization and nutrition benefits of white shrimp
Consumers' information on the utilization and nutritional benefits of white shrimps is presented in table 6.All the respondents said they were aware of the utilization of white shrimps in weaning foods.Only 6 respondents representing 15% of the consumers admitted babies fed food supplemented with white shrimps do show allergic reactions; however, majority (85%) said babies were not allergic to weaning foods supplemented with white shrimps.Furthermore, 77.5% of the respondents were aware of the nutritional benefits of white shrimps while 22.5% were not aware.In addition, 7.5% said they were aware of the nutritional benefits of the shrimp through medical advice, 10% got informed through radio/tele media, 12.5% were through friends, 35% through literature/education, 10% through social media, while 25% said white shrimps was part of their native diet.Twenty percent of the consumers said the shellfish supplies vitamins to the body, 10% said it is proteinous, 37.5% said it aids strong and healthy bones while 25%   said they do not know the nutritional benefits of the shrimp species.

Sensory properties of smoke-dried N. hastatus
Results of the sensory evaluation of smoke-dried shrimps collected from processing units are of great importance to the acceptability of the product among consumers.The significant differences in the organoleptic properties of the species might be attributed to handling, heat intensity, hours of smoking and type of wood used.Guochen et al. (2008) and Yakubu and Nqueku (2015) documented that the physical and sensory properties of dried shrimp (Pandalus borealis) and fish samples were significantly affected by the handling conditions.These might be responsible for low acceptability of A3, B2 and B3; however, samples A1 and B5 were highly accepted than the other samples.This might be credited to their colours, flavour, taste and appearance which were rated better.
Processors in the study areas with dried shrimp with sensory properties less than 6 could still improve on their processing methods (by moderating the hours of smoking, heat intensity, type of wood used and presmoking handling) to increase their acceptability in the market place.
It could be inferred from the regression analysis that the taste of the shrimp was the highest significant factor that determined the acceptability of the species among assessors; followed by appearance.The significance of these factors implies that all the sensory attributes were important in determining general acceptability.This is in tandem with the assertion of Olaniyi et al. (2017) who posited that the overall acceptability or palatability rating of African catfish was a reflection or aggregation of the ratings for all cognitive and qualitative sensory attributes.Similar studies by Yakubu and Nqueku (2015) stated that flavour was the highest important factor that determined general acceptability among consumers of smoke-dried fish collected from different markets in Lafia, Nigeria.Other studies by Barret et al. (2010) and Adeola et al. (2016) reported that the taste, flavour and appearance were the key three sensory factors determining the acceptability of processed shrimp and African catfish in market places; consumers evaluate the visual appearance and colour of food products first, followed by the taste, aroma, and texture.Hence, the high rating of these factors in most of the samples by majority of the assessors might have influenced their decision on the acceptability of white shrimps in the study area.Their decision may have been supported by the assertion of Barret et al. (2010) who opined that shrimp generally have bright natural colour, flavour and firmness (excellent elastic and rigid characteristics), presenting a very good overall quality.

Consumption trend among selected consumers
Consumption trend among selected white shrimp consumers provides a better understanding of frequency of consumption, product form and allergic reactions in consumers.The weekly consumption of white shrimp in the study area would affect marketing, processing and extraction of the species.This is because the consumptive demands of consumers do affect resource extraction and other agent in sea food value chain.This assertion is supported by Ardjosoediro and Neven (2008) who reported that resource extraction of seafood is operated under economic incentive largely determined by agents in fish value chain.The preference for dried shrimp compared to other product forms could be attributed to the fact that N. hastatus is mostly available in dried form in the study area.The perishability of the species predisposes them to spoilage; hence they are usually smoke-dried to increase palatability and shelf life (Centre for Environment Human Right and Development, 2007).According to Akonor et al. (2016), shrimp may easily deteriorate after catch except they are kept in cold storage.However, this method is expensive in coastal communities owing to lack of public power supply, hence traditional methods such as sun drying and smoke-drying are used in producing dried shrimps for marketing and consumption.Though, majority of consumers said they showed no allergic reactions to white shrimp consumption; however, some said they do show allergic reactions such as vomiting/tingling of tongue and stomach.This could be the reason some respondents preferred consuming the shellfish in grounded form to reduce tingling in the mouth and stomach.The high acceptability of dried shrimps to fresh could be as a result of the greater nutritional yield of dried shrimps.This statement is supported by the findings of Hog et al. (2006) who posited that smoked shrimp from nutritional point of view can be considered as a product with good nutritive value.

Consumers' accessibility and satisfaction
The presence of different marketing agent (retailer, wholesalers) connotes that the species could be sourced from different agents in the value chain.This result indicated that most of the consumers did not buy directly from processors.They usually buy from retail outlets and wholesalers markets that were less than 10 min walking distance from their homes.Though, majority of consumers said white shrimp was readily available in market outlets, they were less available and more expensive during the dry season.It thus implies that seasonality affects the supply demand and price of dried shrimps in market outlets.Therefore, consumer's price is expected to be high during the off peak months (November and May) compare with prices in the peak months (June and October).Several literatures have documented the effect of seasonality on the availability of shrimps in Nigeria.These include Ambrose (2004) who reported that the total quantity of shrimps and by-catch combined per landings was higher in wet season than dry season in the coastal artisanal shrimp beam trawl fisheries of Lagos State, Nigeria; Ofor and Kunzel ( 2009) estimated a peak catch per unit effort for N. hastatus between May and November in the coastal areas of Cross River State, Nigeria while Ambrose et al. (2016) reported that seasonal variation affects the catch composition of Nematopalaemon fishery.Generally, shrimp landing during the raining season is characterized by high catches compared with reduced volume and increased price; thus affecting the purchasing power of consumers most especially in rural areas and among low income earners (Akins and Winemiller, 2006;Christopher et al., 2017).
Satisfaction of consumers with white shrimps in market outlets could serve as a verdict on white shrimp processors.This might be attributed to acceptable sensory attributes of shrimp in market places which usually determines consumers' choice and price (Olaniyi et al., 2017;Adeola et al., 2016).However, consumers said they could be less/not satisfied with white shrimps in market places due to off flavour, inadequate taste, odd appearance or the amount of by-catch in the product which accounted for 55% of reasons for non/less satisfaction with smoke-dried products in market places.

Storage information
Mould growth is associated to the level of moisture in shrimps.Hence, majority of consumers could have bought dried shrimps with low level of moisture content that would discourage mould growth while those who said shrimps grew mould in storage could have bought shrimps that had higher water activity which could be attributed to shorter processing hour or storage of the product in humid environment.Mould growth in food generally occurs when storage and/or drying conditions are not optimal.Casa-veneracion (2018) believes that dried shrimp are not exempted from storage spoilage but the degree of spoilage is dependent on the humidity of the environment and storage medium.The writer opined that mould might be the worst enemy of dried shrimps and once they get mouldy; there is no other choice but to throw them away.Eeckhout et al. (2013) equally submitted that mould growth and mycotoxin production in food is affected by moisture content, storage conditions, temperature, and humidity; hence, storage conditions should be well fine-tuned to avoid mould growth.
Storage information is important to consumers, producers and marketers.Though processors in the study area sold their product within the week of smoke/sun drying, retailers and consumers are participants in the value chain that usually stores white shrimps for longer period.The result of storage medium indicated that most of consumers stored white shrimps in cheap and available materials such as nylon, air-tight plastics, plates and bowl.The reduction in the numbers of consumers that stored the shrimp species in refrigerators could be as a result of inadequate electricity, or high cost of refrigerators which lowers it usage compared with 12.5% that used cupboard for this purpose which was less expensive.The length of dried shrimp in storage indicates that species could stay between 30 and 60 days in storage.However, the shelf life of the shellfish in storage could be affected by the medium of storage while the choice of storage medium is determined by cost.Studies by Asinghe et al. (2006) recommended Styrofoam as the best medium for storing processed whole and peeled dried shrimp while Casa-veneracion (2018) recommends storing dried shrimps in a jar with a screw-type cap and kept in the refrigerator as the best medium for increasing shelf life and maintaining product quality which was the form used by 7.5% of the consumers under study.

Acceptability and types of food flavoured with dried N. hastatus
High level of acceptability of food flavoured with N. hastatus among selected consumers is an indication that species was largely accepted in the diets of coastal inhabitants.The excellent sensory attributes (taste, flavour) could also be the reason why the product serves as source of seasoning in the diets of coastal inhabitants and beyond.Okayi et al. (2013) described white shrimps as a major and essential condiment which supplies nutrients to coastal inhabitants and beyond.Ajala and Oyategbe (2013) equally stated that shrimps in its different forms contribute substantially to the diet of Nigerians because of its low price and easy availability; they are major source of animal protein to the low income earners because it is more acceptable than other forms of animal protein as there are no social, cultural or religious taboos associated with its consumption (Bello, 2013).

Utilization and nutrition benefits of white shrimps
Results from the study indicated that all the consumers were aware of the utilization of white shrimps as supplement in weaning foods.This shows that white shrimp was mostly used in the production of weaning food in coastal communities because of its easy accessibility (Bello, 2013).The relevance of this is to reduce malnutrition among the poor who cannot afford expensive supplementary weaning foods.Shehu et al. (2013) revealed that grounded white shrimps were increasingly being used in many developing countries as ingredients in the production of weaning/complementary foods.Most of consumers said babies fed with foods fortified with shrimp showed no allergic reaction while some of the consumers said some children do show allergy to food supplemented with white shrimps.Such allergic reactions include vomiting, tingling, abdominal pain and diarrhea.
Consumers' awareness of the nutritional benefits of white shrimps might be the reason for the high level of acceptance of the species in their diets.Awareness of the nutritional benefits of the species were gotten through different means which include medical advice, social media, television and radio medium, literature texts, friends while 25% of them said white shrimp was part of their native diet.The literacy level of consumers in the study area could have leveraged on their awareness of the nutritional qualities of white shrimps as 95% of them had between primary and tertiary education.The perception of consumers on the nutritional benefits of white shrimps is similar to the Dayal et al. (2011) and Shehu et al. (2013) who stated that dry matter of shrimps are loaded with protein, vitamin D, vitamin B3, iodine and zinc and carbohydrate-free food for anyone determined to shed off weight.Since white shrimps are excellent source of zinc and other micro nutrients; they could be used in supplementing Zn 2+ deficient diets particularly for children (Shehu et al., 2013).

Conclusion
The study emphasized the importance of sensory evaluation and perception of consumers on the quality, acceptance and utilization of white shrimp in coastal areas of Ondo State, Nigeria.All the sensory properties were positively correlated with the general acceptability of smoked samples of the species.By-catches, off-flavour and odd-appearance were the factors that determined consumers' satisfaction with shrimps in market places.Hence, shrimp processors should lay more emphasis on the type of wood, numbers of processing hours and heat intensity applied during processing.They should equally endeavour to thoroughly sort-out by-catches from fresh shrimp before processing.Equally, selective gears should be designed to reduce by-catches at landing; this would further increase consumers' satisfaction and patronage in market places.

Figure 1 .
Figure 1.Map of the study area.

Figure 3 .
Figure 3. Acceptability and types of food flavoured with N. hastatus.Source: Computed from Field Survey (2017).
The area is positioned within the equatorial evergreen swamp forest.It shares boundaries with Okitipupa Local Government Area in the North; the Atlantic Ocean in the South; Ijebu Waterside Local Government Area (Ogun State) in the West and Delta State in the East.

Table 2 .
Effects of sensory properties on acceptability of smokedried shrimp.

Table 3 .
Consumption trend of white shrimp among selected consumers.

Table 4 .
Product accessibility and satisfaction.
Source: Computed from Field Survey (2017).less than ten minutes walking distance, while 12.5 and

Table 5 .
Information on storage.

Table 6 .
Utilization and nutrition benefits of white shrimp.