2.8.2. Thermal stability investigation of immobilized lipase MG10
To test the irreversible thermal inactivation of both form of lipase, the enzyme solution was incubated at revealed temperature for 3 h. At different time interval, aliquots were picked up and examined for remaining activity.
Storage stabilities of the free and coated-MGO-magnetic CLEAs enzyme were also examined by placing enzyme solutions in phosphate buffer (100 mM, pH 7.5) without substrate at 4 °C. Every 2 days, cMGO-CLEAs lipase was picked up by a magnetic and washed by distilled water. After that, the activity of both forms of enzymes was measured as described formerly. The residual enzyme activities were dignified by calculating the original lipase activity as 100%.
2.8.3. Investigation of Kinetic parameters
Kinetic factors of both free and coated-MGO-magnetic CLEAs lipase were examined using diverse concentrations of substrate in 100 mM phosphate buffer (pH 7.0) at 45 °C. In both forms, 2 mg of lipase was used in assay reaction. The amounts of Vmax, Km factors for free and coated-MGO-magnetic CLEAs lipase were considered from line Waver-Burk plot of the initial reaction rates equivalent to different substrate concentrations.
2.9. Biodiesel construction
Enzymatic transesterification reactions were carried out by free and cMGO-CLEAs lipase and maintained for 48 h with a stirring speed of 160 rpm. The reaction consists of 0.4 g oil (oil from Ricinus communis), methanol (1:3 molar ratio between R. communis oil and methanol) and 0.2% enzyme (free or correspond lipase on support) (w/w, based on the oil weight, g). At diverse time intervals (6, 12, 24 and 28 h), 100 µl of reaction blend was picked up and diluted with the same volume of n-hexane solvent. Afterward, the sample was gathered and the upper layer (10 µL) was performed to gas chromatography (GC) investigation for biodiesel measurement (Ji et al., 2010; Wang et al., 2017; Malekabadi et al., 2018).
3. Results and discussion
3.1. Screening and identification of bacterial producing the methanol-tolerant lipase
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Lipase producing bacteria were screened in enrichment culture medium supplemented with olive oil as a sole source of carbon. Furthermore, methanol (30%, v/v) was also used to acquire the methanol tolerant lipase. The clear area around the colonies on the tributyrin agar plate was evaluated as lipase production. The greatest lipolytic strains were also examined on the olive oil plate complemented with phenol red, as a pH indicator. Results showed this isolate was a strain which displayed the maximum pink area around the colony. The 16S rDNA gene of MG isolate was amplified and sequenced (Genbank Accession No. MF927590.1) and compared by BLAST investigation to other bacteria in the NCBI database. The results proposed a near relationship between MG10 isolate and the other members of the Enterobacter genus with a extreme sequence homology (99%) to Enterobacter cloacae. The phylogenetic tree (Fig. 1) designated that the strain MG10 was associated with Enterobacter species and used for the following study.
3.2. Purification and immobilization of the lipase
Cell free supernatant of MG10 stain was exposed to ammonium sulfate precipitation (85% saturation) and Q-sepharose chromatography. Lipase MG10 was eluted from the Q-Sepharose column with a 19.5-fold purification and a 38.1 % yield, and it displayed a specific activity of 442.6 U/mg. This yield of MG10 lipase was analogous to the lipase of S. maltophilia (33.9%) (Li et al., 2013) and lower than lipase from P. aeruginosa PseA (51.6%) (Gaur et al., 2008), but greater than lipase of B. licheniformis (8.4 %) (Sharma and Kanwar, 2017). SDS–PAGE analysis of the MG10 lipase shown that it has a single band about 33 kDa, which it is dissimilar with the other Enterobacter cloacae.
Results of protein measurement with Bradford technique displayed that protein loading on these coated magnetite nanomaterials was succeeded. Moreover, the results of determination of protein loading on these nanomaterials shown that, immobilization efficiency was achieved about 73%. mGO-CLEAs lipase was spread in phosphate buffer. After a magnet was positioned sidewise, mGO-CLEAs Lipase showed fast response (60 seconds) to the peripheral magnetic field. It incomes that the magnetic CLEAs-Lip particles were shown suitable magnetic concern even though layers of CLEAs-Lipase were covered on their surfaces, wherein it is significant in term of lipase immobilization.
2. Review of literature
2.1. Liver overview
2.1.1. Liver anatomy and physiology
The liver is considered to be the largest organ in the human body whose weight ranges from 1200 – 1500g and is located in the upper right portion of the abdominal cavity and is closely associated with the small intestine. It consists of two anatomical lobes where the right lobe is about six times larger than the left one. Lesser segments of the right lobe are the caudate lobe on the posterior surface and the quadrate lobe on the inferior surface. The right and left lobes are separated anteriorly by a fold of peritoneum called the falciform ligament, posteriorly by the fissure for the ligamentum venosum and inferiorly by the fissure for the ligamentum teres CITATION sag l 1033 (Plaats, 2005) CITATION JAM11 l 1033 (Dooley, Lok, Burroughs, & Heathcote, 2011).
Fig. (1): Anterior and posterior views of the human liver
The functional tissue of the liver (parenchyma) is composed of at least seven distinct types of cells : hepatocytes, cholangiocytes, sinusoidal endothelial cells, macrophages, lymphocytes of several different phenotypes, dendritic cells, and stellate cells(Ito cells), all arranged in a matrix that mediates their interaction CITATION Irw09 l 1033 (Arias, et al., 2009). Hepatocytes are polygonal in shape and approximately 30µm in diameter. They comprise about 60-70% of the normal liver parenchyma. During fetal period, hepatocytes are characterized by their highly proliferative capacity. In the adult liver, they are generally quiescent although they are capable of regeneration in response to hepatocyte loss CITATION Dhi09 l 1033 (Haridass, et al., 2009). They contain a high percentage of endoplasmic reticulum as well as enormous number of mitochondria per cell which makes this cell fitted for their regenerative potential CITATION Mal05 l 1033 (Malarkey, Johnson, Ryan, Boorman, & Maronpot, 2005).
Almost all blood that enters the liver passes via the portal tract, (a vessel originates from the gastrointestinal tract as well as from the spleen), pancreas and gallbladder. A second blood supply to the liver comes from the hepatic artery, branching directly from the celiac trunk and descending aorta. The portal vein supplies venous blood with low O2 content to the liver, on the other hand, blood from the hepatic artery which originates directly from the aorta is saturated with O2. Blood from both vessels then joins in the capillary bed of the liver and leaves via central veins to the inferior caval vein CITATION sag l 1033 (Plaats, 2005).
Sinusoids are low pressure vascular channels that receive blood from terminal branches of the hepatic artery and portal vein at the periphery of lobules and deliver it into central veins. They are aligned in a radial form in the lobule and hepatocytes are separated from them by the space of Disse (perisinusoidal space). The sinusoid is the home of non-parenchymal cells which include: 1. Fenestrated sinusoidal endothelial cells, which form the sinusoid lining that is in contact with the blood, 2. Phagocytic Kupffer cells, which adhere on the luminal aspect, 3. Hepatic stellate cells, specialized pericytes that extend processes throughout the space of Disse and serve as myofibroblasts during times of hepatic injury and repair and finally 4. Pit cells, which are immune-reactive natural killer (NK) cells that are attached to the abluminal surface of the sinusoid and are part of a population of liver-associated lymphocytes CITATION San17 l 1033 (Sanyal, Boyer, Terrault, & Lindor, 2017). Circulating proteins and plasma components migrate through these lining cells into the perisinusoidal space where direct contact with the hepatocytes occurs and uptake of nutrients and oxygen occurs. Bile canaliculi are minute channels between adjacent hepatocytes that deliver bile into bile ductules in the portal area. The bile is kept apart from the blood and the space of Disse. CITATION sag l 1033 (Plaats, 2005).
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Hepatic stellate cells (HSC), also known as perisinusoidal cells are pericytes found in the HYPERLINK “https://en.wikipedia.org/wiki/Space_of_Disse” o “Space of Disse” perisinusoidal space of the liver . The stellate cell is the major cell type involved in liver fibrosis, which is the formation of scar tissue in response to liver damage.The body of HSC contains lipid droplets which stores vitamin A. CITATION Win07 l 1033 (Winau, et al., 2007).
Fig. (2): Illustration of part of a mammalian liver lobule by U. Frevert, S. Engelmann, S. Zougbédé, J.Stange, B. Ng, et al., 2005; based on the research article “Intravital Observation of Plasmodium berghei Sporozoite Infection of the Liver”, PLoS Biology, doi:10.1371/journal.pbio.0030192.g011.
Or Diagram showing main cell types of Liver-hepatocytes, endothelial cells, Kupffer cells and Stellate cells. Source: Tissupath specialist pathway services, Retrieved 2017. www. Tissupath.com.au
2.1.2. Liver functions
Cells in the mature liver must perform their role in a coordinated manner for the liver to function properly. Proper liver function is essential for maintaining metabolic homeostasis in mammals. Surprisingly, about 500 separate biochemical processes takes place within one single liver cell. CITATION sag l 1033 (Plaats, 2005). Many organs have a ‘functional unit’ that is defined as the smallest section of the organ that can carry out the basic function of that organ. The liver is divided into ‘classical’ lobules with a central venule in the middle, and in some of the corners of the polygon (typically drawn as a hexagon) surrounding this is a ‘portal triad’ containing branches of the portal vein and the hepatic artery, and a bile duct CITATION Sar09 l 1033 (Sargent, 2009)(Figure.3).
Fig.(3):The structure of the liver’s functional units or lobules. Blood enters the lobules through branches of the portal vein and hepatic artery proper, then flows through sinusoids and leaves via branches of the hepatic vein. Source: Anatomy ; Physiology, Connexions Web site,2013.
Liver performs numerous functions includes:
126.96.36.199. Metabolic functions
The liver has an essential role in the metabolism of carbohydrate, fat, proteins and in detoxification of toxic substancesCITATION Par97 l 1033 (Chandrasoma ; Taylor, 2001)188.8.131.52.1. Carbohydrate metabolism
The liver contributes to maintenance of the physiological blood glucose concentrations as it releases glucose when blood levels are low (hypoglycemia) and takes it up when supply is plentiful (hyperglycemia); a situation regulated by the interplay between insulin and its antagonists. Added to that, glucose is also stored within hepatocytes in the form of glycogen (glycogenesis). Glycogen is readily broken down into glucose (glycogenolysis)CITATION Kun l 1033 (Kuntz ; Kuntz, 2009). During fasting about 11% of glycogen stores are used each hour. After a few hours, the liver increasingly turns to gluconeogenesis to supply glucose. This is the production of new glucose from non-carbohydrates, mainly lactate, amino acids and glycerol (not fatty acids). CITATION Sar09 l 1033 (Sargent, 2009). When there is a glucose deficiency, the liver metabolizes fatty acids to form keton bodies, which represent an alternative energy source for many tissues CITATION Kru99 l 1033 (Kruszynska, 1999).
184.108.40.206.2. Fat metabolism
The liver plays an essential role in the digestion of dietary fats. It produces bile salts which are essential to emulsify fat substances within the gut. Almost all fats in the diet are absorbed from the intestines into the lymphatic system. The fats are broken down into monoglycerides and fatty acids that are absorbed into the intestinal epithelial cells and then enter the lymphatic system as tiny, dispersed particles called chylomicrons. Therefore, functions of the liver in the metabolism of fat can be summarized as, uptake and oxidation of fatty acids to supply energy, synthesis of cholesterol, phospholipids and lipoproteins as well as conversion of proteins and carbohydrates into fats. CITATION Sar09 l 1033 (Sargent, 2009)CITATION Can07 l 1033 (Canbay, Bechmann, ; Gerken, 2007).
220.127.116.11.3. Protein metabolism
The liver participates in protein metabolism in many different aspects such as deamination and transamination of amino acids, followed by conversion of the non-nitrogenous part of those molecules to glucose or lipids. Moreover, it is responsible for synthesis of non-essential amino acids. Several of the enzymes involved in these previous pathways (for example, alanine and aspartate aminotransferases) are commonly produced by the liver and are assayed in serum to assess liver damage. Additionally, ammonia, the highly toxic substance which has harmful effects on the body if accumulates, is removed by the liver in the form of urea. Albumin and other plasma proteins are essentially synthesized within hepatocytes CITATION Ber02 l 1033 (Berg, Tymoczko, ; Stryer, 2002).
18.104.22.168. Synthesis of clotting factors
Also, the liver produces many of the clotting factors necessary for blood coagulation and their inhibitors CITATION Ami02 l 1033 (Amitrano, Guardascione, Brancaccio, ; Balzano, 2002). Clotting factors are protein in nature. They include coagulation factors I (fibrinogen), II (prothrombin), V, VII, VIII, IX, X, XI, XIII, as well as protein C, protein S and antithrombin. The liver is a major site of production for thrombopoietin, a glycoprotein hormone that regulates the production of platelets by the bone marrow CITATION Jel01 l 1033 (Jelkmann, 2001).
22.214.171.124. Detoxification function and drug processing
According to CITATION Kun l 1033 (Kuntz ; Kuntz, 2009), removal of endogenous and exogenous substances from the body is necessary as long as they are not serviceable in energy production, not needed for the maintenance of structure, or cannot be stored without causing detrimental effects on the body. As a result, xenobiotics (foreign bodies) and harmful substances must be broken down and/or detoxified then converted to a water-soluble state in order to be excreted in the stool or urine. The liver is considered to be the principle organ for the detoxification processes of the injurious nitrogenous compounds derived from the intestine and many drugs and chemicalsCITATION Par97 l 1033 (Chandrasoma ; Taylor, 2001).
126.96.36.199. Exocrine function
Approximately about 500 mL of bile is secreted daily by the liver. It consists mainly of water, inorganic electrolytes as well as organic solutes such as bile salts which have a detergent-like effect in the gut lumen, emulsifying dietary fat in order to facilitate its digestion. Bile is continuously secreted by hepatocytes into biliary canaliculi. Between meals contraction of the sphincter of Oddi causes bile to accumulate in the gallbladder where the bile salts are concentrated CITATION Sar09 l 1033 (Sargent, 2009).
2.1.3. Liver diseases
Liver diseases affect the normal functions of the liver. Liver capacity for regeneration following a single damage is excellent. A hepactectomy may involve the removal of two thirds of the liver, but the remaining hepatocytes can reproliferate to restore the mass of the organ within days to weeks CITATION Gua06 l 1033 (Guangsheng ; Steer, 2006).
188.8.131.52. Acute vs. chronic liver diseases (?????)
An acute illness is one that lasts less than six months while a chronic illness lasts more than six months. A patient with a chronic liver disease may have few or no symptoms for some time, until the disease worsens and symptoms suddenly become apparent. In some viral infections, an individual suddenly becomes ill and displays a variety of symptoms, such as chills, fever and vomiting. Although some viral infections can be serious, even deadly, the infection usually runs a swift course, and the patient recovers within a few days. The possibility of the acute liver disease to turn chronic is still present, however it often depends on the causative agent. Hepatitis A and hepatitis E, for example, never turn chronic; the vast majority of hepatitis C cases, however, do become chronic. When a patient is suffering from acute liver disease, the goal is to cure the patient and keep the disease from becoming chronic. In contrast, the onset of the chronic disease is often less clear and more insidious than that of an acute illness. Hepatitis C, for example, usually displays no obvious early symptoms. Most individuals infected with hepatitis C are not even aware that they have become infected. It can last alifetime unless the individual receives medical treatment, and even then only half the patients manage to eliminate the virus from their bodies. With chronic disease, the goal is to cure the disease if possible, to keep it from becoming worse, or to control the complications that may occur. In the case of liver disease, that means keeping the disease from progressing to cirrhosis, in which the scarring is so extensive that the liver becomes distorted and often develops cancer. If cirrhosis is already present, the goal of treatment is to prevent further deterioration of liver function and to control the complications CITATION Jam06 l 1033 (Chow ; Chow, 2006).
184.108.40.206. Liver inflammation (Hepatitis)
Hepatitis refers to an inflammatory condition of the liver which has multiple causes. It’s commonly triggered by a viral infection however, autoimmune hepatitis and hepatitis that occurs as a secondary result of medications, drugs, toxins, and alcohol are also taken into consideration. It is characterized by the presence of inflammatory infiltrates in the tissue of the organ CITATION Tin l 1033 (Lee & Dienstag, 2015).
220.127.116.11.1. Viral hepatitis
Viral hepatitis is the most common type of hepatitis worldwide where the liver undergoes inflammatory conditions due to a viral infection. Viral hepatitis is caused by five different viruses (hepatitis A, B, C, D, and E). Both hepatitis A and hepatitis E behave similarly and share the same etiology which is ingesting food or water contaminated by feces from a person infected with the virus. The latter viral infections are more common in developing countries, and do not turn to chronic hepatitis CITATION Kum15 l 1033 (Kumar, Abbas, & Aster, 2015).
Hepatitis B, hepatitis C, and hepatitis D are transmitted when blood or mucus membranes are exposed to infected blood and body fluids, such as semen and vaginal secretions. Hepatitis B and C can present either acutely or chronically. Hepatitis D is a defective virus that requires hepatitis B to replicate and is only found with hepatitis B co-infection CITATION Mys18 l 1033 (Mysore & Leung, 2018). In adults, hepatitis B infection is most commonly self-limiting, with less than 5% progressing to chronic state, and 20 to 30% of those chronically infected developing cirrhosis and/or liver cancer. However, infection in infants and children frequently leads to chronic infection CITATION Eug11 l 1033 (Schiff, Maddrey, & Sorrell, 2011).
18.104.22.168.2. Alcoholic hepatitis
Alcoholic liver disease (ALD) is one of the most widespread liver diseases which occurs as a result of excessive alcohol consumption and it is usually associated with fatty liver, an early stage of ALD that may lead to the progression of fibrosis and end upwith cirrhosis making ALD a major cause of mortality CITATION Tor15 l 1033 (Torok, 2015). Alcohol abuse negatively affects all organs within the body especially the liver being the body’s first line of defense against toxins. Liver metabolizes any ingested alcohol into less toxic by-products, and converts fat-soluble substances into water-soluble substances for elimination CITATION Jam06 l 1033 (Chow ; Chow, 2006).
22.214.171.124.3. Drug-induced hepatitis
Drug-induced hepatitis (DIH), also known as toxic hepatitis, is caused by ingesting medications by mouth or by injection CITATION Jam06 l 1033 (Chow ; Chow, 2006). Chemical agents such as medications, industrial toxins and dietary complements that enters the body’s circulation must undergo biotransformation within the liver due to its chief role in the process of detoxification and drug metabolism. Liver injury due to drugs can vary from acute hepatitis to chronic hepatitis to acute liver failure CITATION Tin l 1033 (Lee & Dienstag, 2015). DIH can results in liver inflammation via various mechanisms such as direct cellular damage , disruption of cell metabolism, and causing structural deformationsCITATION Wil03 l 1033 (Lee W. M., 2003) and CITATION Law15 l 1033 (Lawrence & Friedman, 2015).
126.96.36.199.4. Autoimmune hepatitis (AIH)
Autoimmune hepatitis (AIH) is a chronic disease in which the body’s immune system attacks the normal components, or cells, of the liver and causes inflammation and liver damage . It is characterized by hypergammaglobulinemia, autoantibodies detection and interface hepatitis and is considered a serious medical situation that may worsen over time if not treated CITATION Gat15 l 1033 (Gatselis, Zachou, Koukoulis, ; Dalekos, 2015). Autoimmune hepatitis can lead to cirrhosis and liver failure. CITATION Ans11 l 1033 (Lohse ; Mieli-Vergani, 2011).
188.8.131.52. Liver Fibrosis
Hepatic fibrosis is a scarring process that is associated with an increased and altered deposition of extracellular matrix (ECM) in almost all patients with chronic liver injury CITATION Eug11 l 1033 (Schiff, Maddrey, ; Sorrell, 2011). Undoubtedly, activation of hepatic stellate cells (HSCs) is the crucial event in hepatic fibrosis. These perisinusoidal cells secrete large amounts of matrix proteins in a form of scar tissue in response to an injury. Their mode of action is mediated not only by cytokines and chemokines but also by non-peptide signals such as reactive oxygen species, lipid mediators and prostaglandins CITATION Pin04 l 1033 (Pinzani ; Rombouts, 2004). Hepatic damage that initiates the fibrotic process can be a result of different numerous causes including excessive alcohol abuse, viral hepatitis, drugs, toxins and autoimmune liver disease. Advanced liver fibrosis results in cirrhosis, liver failure, and portal hypertension and often requires liver transplantation CITATION Ram05 l 1033 (Bataller ; Brenner, 2005).
184.108.40.206. Liver Cirrhosis
CITATION Sch08 l 1033 (Schuppan ; Afdhal, 2008) defined cirrhosis as the histological development of nodules of regenerating hepatocytes surrounded by dense fibrotic septa formed in response to chronic liver injury. The latter case produces hepatocellular dysfunction, increased intrahepatic resistance to blood flow, which results in hepatic insufficiency, portal hypertension and end stage liver disease CITATION Gin04 l 1033 (Gines, Cardenas, Arroyo, ; Rodes, 2004) CITATION McC l 1033 (McCormick, 2011). The primary causes of hepatic cirrhosis determine its rate of progression, years or decades, and its treatment strategy. For this reason, it can thus be prohibited by proper screening for chronic liver diseases so that a personalized treatment plan can be applied in time CITATION Wie13 l 1033 (Wiegand ; Berg, 2013). Currently, liver transplantation remains the only curative option for a selected group of patients, however, drug therapies that can stop progression to decompensated cirrhosis or even reverse cirrhosis are now being developed CITATION Sch08 l 1033 (Schuppan ; Afdhal, 2008).
220.127.116.11. Hepatocellular carcinoma
Hepatocellular carcinoma (HCC), also called malignant hepatoma, is the most common type of liver cancer and is a growing cause of cancer related mortality. Most cases of HCC are as a result of either a viral hepatitis infection (hepatitis B or C), metabolic toxins such as alcohol or HYPERLINK “https://en.wikipedia.org/wiki/Aflatoxin” o “Aflatoxin” aflatoxin), conditions like hemochromatosis and alpha 1-antitrypsin deficiency or non-alcoholic steatohepatitis (NASH) CITATION Kum15 l 1033 (Kumar, Abbas, ; Aster, 2015). Cirrhosis is the most important risk factor for developing HCC and is present in 80% to 90% of individuals. Treatment options for HCC and prognosis are dependent on many factors but especially on tumor size, staging, and extent of liver injury CITATION Wag15 l 1033 (Waghray, Murali, ; Narayanan Menon, 2015).
2.3 Brand Association
2.3.1 Definition of Brand Association
Brand association refers to anything that the consumer connects to the brand (Aaker 1996). These associations will then help the consumers to remember and process relevant information that will enable them to make a purchase decision (Aaker 1996; George, et al. 2000). According to Keller (1993), there are different levels of abstraction for various brand association. In his study, he introduces a conceptual model of brand association, by dividing it into three different groups based on level of abstraction.
On the first level of abstraction, I find brand attributes. This group consists of the tangible and intangible attributes that make up the product features. The second level is the customer benefits (Keller 1993). This level relates to the consumers’ individual valued benefits from the use of the attributes. Finally, the third level of abstraction is brand attitude. It is seen as a function of the associated brand attributes and customer benefits (Keller 1993). Brand attitude can be described as a multiplicative function that, apart from the extent to which consumers believe a brand has certain attributes and benefits, also consider whether these attributes and benefits are positive or negative for a consumer.
The brand associations can, in turn, be of different levels of importance, based on strength, favorability, and uniqueness. Strength relates to how strongly the brand association dimension is linked to a particular brand. Favorability is the degree to which consumers find that the brand association dimension is favorable for a certain product category or brand. Finally, uniqueness describes how divergent a particular brand association dimension is for a brand in a certain product category. These levels of importance are factors that will determine consumers’ overall perceptions of a brand.
2.3.2 Brand association and brand image
A concept that closely relates to brand association is brand image. In Keller (1993), brand image is defined as a consumer’s general brand perception. It is generally accepted to connect brand image to the associative network memory model, which explains how the consumers’ perceptions of a brand are related to the associations in their memory. Keller also concludes that different brand associations have a cause and effect relationship with brand image, which is further confirmed by Faircloth et al. (2001). Simply put a change in brand association results in a change in brand image. I will elaborate on this relationship and its implications further in our discussion.
2.4 Product knowledge
A lot of research show that consumers’ knowledge and experience regarding a product could impact the way a product is evaluated (Fu ; Elliott 2013). Maheswaran (1994) defines product knowledge as the knowledge that consumers have regarding a certain product. In this thesis, I will define product knowledge as the level of knowledge consumers has about a certain product, as perceived by the consumers themselves.
According to Alba (1983), people with higher levels of product knowledge are able to recall more total information about explicit product features, compared those with lower levels of product knowledge. Moreover, Maheswaran (1994) suggests that a consumer’s product knowledge acts as a moderating variable for country of origin in product evaluation. In his study, Maheswaran found that when product attributes are explicit, consumers with high product knowledge tend to rely more on these attributes rather than country of origin, when evaluating products.
2.5 Hypothesis development
2.5.1 Brand origin effect on brand association
I want to test the effect brand origin will have on brand association in terms of my chosen dimensions. In Samiee (1994) it was concluded that brands associated with a certain country, could either positively or negatively affect consumers’ perceptions of a brand. In addition, Han (1989) and Schooler (1965), also suggest that country of origin has an effect when consumers evaluate brands. This leads us to my first hypothesis:
H1: Brand origin will have a significant effect on consumer’s brand association in terms of my chosen brand association dimensions
2.5.2 Brand association dimensions
To test my research question, we identify five brand association dimensions: quality, innovation, CSR, prestige, and safety and integrity. Based on Keller’s theoretical definition of brand association, the term in itself is determined by the consumers’ own perceptions of brand attributes, consumer benefits, and brand attitude. Testing for brand association dimensions will, therefore, test consumers’ perceptions. In this thesis, the use of the terms quality, innovation, CSR, prestige, and safety and integrity will refer to consumers’ perceptions rather than objective measures. These brand association dimensions are selected because they are considered to have theoretical and managerial relevance for my research field.
In my study, I refer to quality as the degree to which the product attributes of a specific product satisfy the wants of a specific consumer (Gilmore 1974). The quality dimension of brand association shows to be affected by country of origin, according to various studies (Wang and Lamb 1980; Bilkey and Nes 1982). This dimension is therefore relevant when testing for the brand origin effect as well. Previous studies that have tests country-of origin and brand origin show that the quality differs, depending on country of origin (Bilkey and Nes 1982).
Chinese companies are still considered low quality compared to other more developed countries (The Economist 2015). In addition, since the smartphone market today, consists of brands primarily originating from more developed countries. My hypothesis will thus be:
H2a: Ethiopian consumers will rate a brand originating from China lower in quality, compared with brands from other countries.
In this thesis, innovation is referred to as the creation of new knowledge and ideas to facilitate new business outcomes, aimed at improving internal business processes and structures and to create market-driven products and services (Du Plessis 2007, p.3). Innovation is an important dimension for all companies, in order to be competitive (Pauwels et al. 2004). Adding innovation as a brand association will provide a new and interesting insight to research on the brand origin effect. Furthermore, innovation has been included in as a dimension in many other marketing research studies, although not in the field of brand origin (Aaker 1996).
The reason why this is relevant in the context of brand origin is that China had, and still has an image of being good at “copying, absorbing and adapting existing technology and knowledge from around the world” rather than inventing new innovations, according to (Roth et al. 2015). The hypothesis will thus be:
H2b: Ethiopian consumers will rate a brand originating from China lower in innovation, compared with brands from other countries.
In my thesis, corporate social responsibility (CSR) will refer to “the continuing commitment by business to behave ethically and contribute to economic development, while improving the quality of life of the workforce and their families, as well as of the local community and society at large” (World Business Council for Sustainable Development 2008). CSR has gained much attention in recent years within the academic world and it is generally agreed that the importance of CSR in the management of business-society relationship is increasing (Klein and Dawar 2004; Porter and Kramer 2006). Moreover, CSR has been proven to be especially important and valuable for global organizations, and for defining global reputation and brand (Valor 2005; Lewis 2003).
I am including this dimension as it provides a new and highly relevant perspective on how brand origin might affect the brand association dimension, and in turn also the perceived brand image. China is becoming more globally integrated, and its corporations are gaining more economic and social influence. Thus, much attention is being put on CSR among Chinese companies, often from a critical perspective including business scandals, food scares, labor and environmental issues (Ip 2009). My hypothesis will thus be:
H2c: Ethiopian consumers will rate a brand originating from China lower in CSR, compared with brands from other countries.
In this thesis, prestige is referred to as an element that satisfies an emotional desire for a consumer, in terms of a product’s subjective benefits that could be viewed as a signal of status (Vigneron and Johnson 1999). Apart from consumer benefits that originate from the physical features of a product, hedonic motivators are as equally important and relevant for marketers to keep in mind, according to Arnold and Reynolds (2003). Research tells that consumers often tend to evaluate products and services in terms of emotional consumer benefits, such as social belongingness and identity. Since research suggests that prestige is directly related to symbolic and hedonic value (Vigneron and Johnson 1999), I have therefore chosen to include this as a dimension. Moreover, recent marketing research (Matarazzo and Resciniti 2013) includes prestige as a dimension when studying country of origin effect. This makes it interesting and relevant to test this brand association in a new research context such as mine.
Many reports have revealed that international brands are perceived more prestigious compared with local brands among Chinese retail consumers (Deloitte 2010). At the same time, Chinese brands are not considered very prestigious by international consumers (Fan 2006). Bearing this in mind, our hypothesis will thus be:
H2d: Ethiopian consumers will rate a brand originating from China lower in prestige, compared with brands from other countries.
18.104.22.168. Safety and integrity
I define safety and integrity as the feeling of personal integrity, trustworthiness toward a brand and the absence of danger, risk or threat when using a product or service. Similar to prestige, this is also a dimension that focuses on the emotional consumer benefits of buying certain brands. This dimension is especially interesting to consider due to the political views in China regarding censorship and privacy concerns, that are to a great extent different from the ones in Ethiopia. Just like CSR, this is a dimension that has most likely been affected by international media reports (Ip 2009). The increasing amount of Chinese firms that enter the Ethiopian market is often portrayed by Ethiopian media in a skeptical way, often remarking risking our national security and personal integrity
(Palmstierna and Dreyer 2009; Nordlund 2017). Due to this, our hypothesis will thus be:
H2e: Ethiopian consumers will rate a brand originating from China lower in safety and integrity, compared with brands from other countries.