Avocado Pear Pulp ( Persea americana )-Supplemented Cake Improved Some Serum Lipid Profile and Plasma Protein in Rats

Abstract

Avocado pear pulp (Persea americana) is indigenous to Mexico. It is widely cultivated and consumed all over the world. Its oil is rich in monounsaturated fatty acids (SFAs) and can be used to replace SFAs in a diet to lower low-density lipoprotein (LDL) and raise high-density lipoprotein (HDL). Consumers seek healthy foods that aid in reducing metabolic syndrome. The aim of this study is to evaluate the effects of the best acceptable cakes supplemented with 0%, 10%, 30%, and 50% avocado on the serum lipid profile and plasma protein in rats. Twenty-five rats separated into five groups of four test groups and one control group were fed individually for 14 days, after which blood samples were withdrawn and subjected to biochemical analysis. Intake of cake supplemented with avocado pear pulp resulted in significant (P < .05) increment in the body weight, total cholesterol, triglycerides and HDL, and serum protein and decrement in LDL of the rats. The group fed 50% supplemented cake showed highest increase in HDL and least decrease in LDL. Cake supplemented with 50% avocado pear pulp proved to be a better supplementation in reducing serum LDL and increasing serum HDL and serum protein in rats, indicating to be a promising nutraceutical for the management of cardiovascular diseases and its associated complications.

Introduction

Avocado fruits are widely consumed due to its benefits in reducing cardiovascular disease risks. Consumption of high-fat and sugary foods contributes to risk factors of heart diseases such as weight gain, high blood pressure, and increase in blood cholesterol levels. They originated in Mexico and grow widely in many tropical climates. Avocados provide good amount of monounsaturated fatty acids (MUFA). The MUFA may be used to replace saturated fatty acids in a diet to reduce low-density lipoprotein cholesterol (LDL-C) and raise high-density lipoprotein cholesterol (HDL-C).¹ Avocados also contain vitamins and minerals such as A, B, C, E, and K, iron, copper, phosphorus, magnesium, and potassium and a good source of protein, fiber, and beneficial phytochemicals such as β-sitosterol, glutathione, and lutein. The β-sitosterol has the ability to reduce cholesterol.^1,2 Benefits of avocados include high nutritional density, source of major antioxidants, stroke prevention, and good fruit protein and fiber, which is satiating and useful for weight loss.^3,4

Consumption of baked products such as bread, cakes, biscuits, and cookies has greatly increased due to urbanization, ready-to-eat convenience, and availability of various products with varying taste and textural characteristics, as well as their high nutritional profile and longer shelf life.^5,6 Cakes are baked products made from flour, eggs, sugar, shortenings or fat, leavening agents, and some flavorings and are high in calorie, fat, and sugar.⁷ Fat plays a role of incorporating air during mixing and leavening of the product,⁸ tenderizes the crumb, and improves mouth feel. It also contributes to the appearance and aroma of the product.⁹ Complete removal of shortening from a cake production decreases volume, and crumb becomes less tender and the cell structure becomes uneven.¹⁰ Carbohydrate-based fat replacers are one of the options available for partial replacement of fat in cake.⁷

Cakes are used during celebrations such as weddings, birthdays, and anniversaries and other happy occasions or as snack. Nowadays, foods are consumed not only to satisfy hunger but also to provide necessary nutrients for humans, to prevent nutrition-related diseases, and improve physical and mental wellbeing of consumers.¹¹ Increased consumption of food high in fat is associated with the development of atherosclerosis, which is a deposition of lipid in the inner layer of arterial walls. This can occur as a result of a disorder of lipid transport and metabolism.

Epidemiological studies have indicated that diet rich in fruits, vegetables, and spices is related to a low risk of cardiovascular diseases. This study was therefore designed to evaluate the effects of best acceptable avocado supplemented cakes after sensory evaluation on the serum lipid profile and plasma protein in normal adult male Wister rats.

Materials and Methods

Sample collection and preparation

The Bacon specie of Avocado pear pulp (Persea americana) was obtained from Nkwo Ibagwa Local Market in Igbo-Eze South Local Government Area of Enugu State, Nigeria and identified at the Department of Plant Science and Biotechnology, University of Nigeria, Nsukka. The avocado fruits were procured at commercial maturity and kept at room temperature (27°C) for 3 days to complete the ripening process, at which it yielded to gentle pressure when held in the palm of the hand and squeezed. The ripped fruits were washed under running portable water. The fruits were peeled, deseeded, and cut into four wedges. These were cut into small pieces and were finally homogenized using a Binatone domestic food blender (5080 MP) at speed four. Thirty milliliter of lemon juice per 100 g of the pulp was added to prevent enzymatic browning. The cake samples were prepared using creaming method as described by Campbell et al. ¹² with slight modifications.

The composition of the cakes, oven temperature, baking time and yield are shown in Table 1. Cakes were produced with graded levels (10%, 20%, 30%, 40%, and 50%) of avocado pear pulp. For each cake recipe the sugar and fat were creamed for 20 min at speed 2 in a Binatone domestic food blender (5080MP) till it became soft and fluffy. The well-beaten eggs were added and mixed in at the same speed for 4 min. The flour and baking powder screened through 500 μm mesh were added and the batter was mixed at speed 2 for 1 min and later at speed three for 3 min. After scrapping down the bowl, the batter was mixed for an additional 1 min at speed 3. Cake batter was weighed into a greased and floured aluminum foil cake pan. The cake batters were baked in an oven (Carma, Model 1945XL; Terim Group Italy) at 160°C for 25 min to allow the cake batter rise gradually before the structure sets and later increased to 180°C until doneness at the time shown in Table 1 for individual cake mixtures. The increase to 180°C is to avoid falling of cake in the center before it sets. After removal of cakes from the oven, cakes were allowed to cool in the pans for 3 min before the cakes were removed from the pans and further cooled for 60 min on baking sheets before they were wrapped in transparent films to avoid surface drying and stored at room temperature (∼25°C) for 24 h. The prepared cakes were subjected to sensory evaluation to select the three best acceptable cakes (90:10%, 70:30%, and 50:50%, fat: avocado pulp), in addition to nonsupplemented cake for the animal study. The selected cakes were ground with an electric blender and dried in a hot air oven at 60°C for 12 h till it became crispy.

Table 1.

Composition of the Cakes, Oven Temperature, Baking Time and Yield

	Wheat flour (g)	Simas margarine (g)	Avocado pear pulp (g)	Sugar (g)	Egg (g)	Baking powder (g)	Baking time (minutes)	Oven temp (°C)	Yield (g)
AVC₀	800	500	0	500	500	5	90	180	2020
AVC₁₀	800	450	50	500	500	5	130	180	2040
AVC₂₀	800	400	100	500	500	5	130	180	2000
AVC₃₀	800	350	150	500	500	5	130	180	1920
AVC₄₀	800	300	200	500	500	5	120	180	1960
AVC₅₀	800	250	250	500	500	5	120	180	1940

AVC₀, nonsupplemented cake; AVC₁₀, cake supplemented with 10% avocado pear pulp; AVC₂₀, cake supplemented with 20% avocado pear pulp; AVC₃₀, cake supplemented with 30% avocado pear pulp; AVC₄₀, cake supplemented with 40% avocado pear pulp; AVC₅₀, cake supplemented with 50% avocado pear pulp.

Experimental design and feeding trials

Twenty-five locally bred adult male Wister rats (140–180 g), 24 weeks old, were obtained from the Department of Animal Science, Faculty of Agriculture, University of Nigeria, Nsukka, and were handled in accordance with the Guide for the Care and Use of laboratory animals. The rats were housed in individual plastic metabolic cages, weighed, and randomly allocated to four experimental groups and one control group, in groups of five on the basis of their body weight to achieve a mean weight difference of ±5 g among the groups. The control group was fed with rat chow, while the experimental groups were fed with the experimental diets of 0%, 10%, 30%, and 50% supplementation, respectively. The individual weights of the rats were taken at the beginning of the experiment, twice weekly, and at the end of the experimental period to determine weight gained/lost. The first 4 days were used to acclimatize the rats, while 14 days were used for the trial feeding period. Tap water, the experimental diets, and the normal rat feed were given ad libitum for 14 days. Body weights of the rats were recorded. Daily food intakes of the rats were recorded and this was obtained by recording the amount/portion of food given and subtracting the left over after a daily intake. The data were used to determine the total food intake of the rats.

Biochemical assays

Blood samples were withdrawn from the rats through ocular veins on the 5th and 18th day into sample bottles and allowed to clot to separate the serum from the red blood cells. Serum lipid profile, namely, triglycerides (TG), total cholesterol (TC), and HDL and LDL levels were estimated using Liebermann-Burchard reaction method.¹³ Total plasma protein was determined using the biuret method.¹⁴

Statistical analysis

The data obtained were analyzed using Statistical Package for Service Solution (SPSS) version 21.0 for mean and standard error of mean. ANOVA (analysis of variance) and Duncan's new multiple range test were used for the separation of the mean and to compare means (significance at P < .05), respectively.

Results

Table 2 presents the mean food intake and body weights of rats fed rat chow, supplemented and nonsupplemented cakes. There was no significant (P > .05) difference in mean food intake among the groups at the end of 7-day feeding. Significant (P < .05) difference was observed in food intake at the end of 14-day feeding. The group fed 50% supplemented cake recorded highest % decrease in food intakes, while the group fed nonsupplemented cake showed highest % increase in food intake (5.71%) compared to the groups fed rat chow or supplemented cakes.

Table 2.

Mean Food Intake and Body Weights Gain of Rats Fed Rat Chow, Supplemented and Nonsupplemented Cakes

	Rat groups	% avocado pear pulp supplementation	7-day feeding (g)	14-day feeding (g)	% difference
Food intake	RAC₁	—	17.88^a ± 1.74	18.47^c ± 0.51	3.30↑
	AV	0	16.30^a ± 2.44	17.23^bc ± 0.67	5.71↑
	AVC₁	10	16.96^a ± 1.47	16.42^ab ± 0.68	−3.18↓
	AVC₃	30	17.27^a ± 2.04	18.00^c ± 1.40	4.23↑
	AVC₅	50	17.13^a ± 2.07	15.77^a ± 1.65	−7.94↓
Body weight	RAC₁	—	164.05^a ± 6.08	170.48^a ± 4.45	3.92↑
	AV	0	163.75^a ± 8.84	183.24^ab ± 12.51	11.90↑
	AVC₁	10	162.16^a ± 8.88	191.43^b ± 15.83	18.05↑
	AVC₃	30	162.38^a ± 6.03	182.69^ab ± 14.18	12.51↑
	AVC₅	50	161.90^a ± 6.82	172.59^a ± 10.81	7.27↑

Data are mean ± SEM values; n = five; means with different superscripts in the same column differ significantly by Duncan New Multiple Range Test (P < .05). Arrow up means “increase in % difference”; Arrow down means “decrease in % difference”. RAC_1, rat chow (poultry growers mash); AV, nonsupplemented cake; AVC₁, cake supplemented with 10% avocado par pulp; AVC₃, cake supplemented with 30% avocado pear pulp; AVC₅, cake supplemented with 50% avocado pear pulp. $% d i f f e r e n c e = \frac{14 d a y s i n t a k e (g) - 7 d a y s i n t a k e (g)}{7 d a y s i n t a k e (g)} \times 100 %$

There was significant (P < .05) difference in mean body weight of the rat groups at the end of 14-day feeding. The group fed 10% supplemented avocado pear pulp had the highest percentage increase in body weight, while the groups fed 50% cake revealed least percentage mean weight gain among the groups fed the test cakes. The rats fed rat chow showed the least decrease.

Table 3 presents the serum lipid profile of rats fed rat chow, supplemented and nonsupplemented cakes. There were significant differences in TC levels of the five groups of rats. The groups fed 0%, 10%, and 50% supplemented avocado pear pulp cakes had comparable percentage increases in TC with the group fed nonsupplemented (0%), except the rats fed 30% supplemented cake, which had significantly (P < .05) lower TC than the other test groups. The least increase was found in rats fed rat chow.

Table 3.

Mean Serum Lipid Profile of Rats Fed Rat Chow, Supplemented and Nonsupplemented Cakes

	Rat groups	% avocado pear pulp supplementation	7 days before feeding (mg/dL)	14 days after feeding (mg/dL)	% difference
TC	RAC₁	—	119.10^b ± 0.53	122.19^b ± 0.39	2.60↑
	AV	0	87.01^a ± 0.17	108.66^ab ± 0.20	24.88↑
	AVC₁	10	83.14^a ± 0.15	102.09^ab ± 0.37	22.79↑
	AVC₃	30	85.46^a ± 0.10	100.54^a ± 0.36	17.65↑
	AVC₅	50	83.91^a ± 0.19	105.96^ab ± 0.50	26.27↑
TG	RAC₁	—	47.95^b ± 0.10	52.59^a ± 0.08	9.68↑
	AV	0	42.15^a ± 0.11	63.42^a ± 0.14	50.46↑
	AVC₁	10	41.38^a ± 0.05	68.06^a ± 0.45	64.49↑
	AVC₃	30	40.22^a ± 0.07	67.67^a ± 0.39	68.27↑
	AVC₅	50	41.76^a ± 0.15	65.35^a ± 0.54	56.48↑
LDL	RAC₁	—	15.08^a ± 0.24	18.56^b ± 0.24	23.08↑
	AV	0	15.47^a ± 0.10	5.80^a ± 0.07	−62.50↓
	AVC₁	10	22.82^a ± 0.05	6.96^a ± 0.05	−69.49↓
	AVC₃	30	20.11^a ± 0.18	8.89^a ± 0.09	−55.76↓
	AVC₅	50	22.04^a ± 0.07	11.99^a ± 0.09	−45.61↓
HDL	RAC₁	—	47.56^b ± 0.14	51.82^b ± 0.13	8.94↑
	AV	0	18.95^a ± 0.05	25.14^a ± 0.07	32.65↑
	AVC₁	10	23.98^a ± 0.10	32.09^a ± 0.23	33.87↑
	AVC₃	30	23.20^a ± 0.99	30.55^a ± 0.25	31.67↑
	AVC₅	50	21.66^a ± 0.78	38.28^ab ± 0.48	76.79↑

Data are mean ± SEM values; n = five; means with different superscripts in the same column differ significantly by Duncan New Multiple Range Test (P < .05). Arrow up means “increase in % difference”; Arrow down means “decrease in % difference”. RAC₁, rat chow (poultry growers mash); AV, nonsupplemented cake; AVC₁, cake supplemented with 10% avocado pear pulp; AVC₃, cake supplemented with 30% avocado pear pulp; AVC₅, cake supplemented with 50% avocado pear pulp; TC, total cholesterol; TG, triglyceride; LDL, low-density lipoprotein; HDL, high-density lipoprotein. $% d i f f e r e n c e = \frac{L i p i d p r o f i l e a f t e r f e e d i n g - L i p i d p r o f i l e b e f o r e f e e d i n g}{L i p i d p r o f i l e b e f o r e f e e d i n g} \times 100 %$

The result revealed that serum TGs showed slight, but comparable increase in the five groups. The group fed rat chow recorded least increase. The serum LDL of the five groups showed comparable decrease, except the control group fed rat chow, which showed percentage increase. Among rats fed on supplemented and nonsupplemented cakes, the group fed supplemented 10% avocado pear pulp cake had the highest percentage decrease in LDL and the least decrease was found in rats fed cake supplemented with 50% avocado pear pulp.

Data on HDL indicated significant differences among the groups. The groups fed either supplemented or nonsupplemented cakes had high percentage increase in HDL when compared with the control group. Among groups fed supplemented or nonsupplemented avocado pear pulp cakes, the group fed 50% supplemented avocado pear pulp cake had the highest percentage increase in HDL, while other groups had comparable levels, except the control group, which recorded the least.

Table 4 presents the plasma protein of rats fed rat chow, supplemented and nonsupplemented cakes. There was significant (P < .05) percentage increase in plasma protein among the rats fed rat chow or supplemented or nonsupplemented cake. The control group had the highest percentage increase in plasma protein when compared to other groups. There was percentage increase in plasma protein as the supplementation increases. The percentage difference in plasma protein of the rats fed 50% supplemented cake was higher than the other cake-fed groups.

Table 4.

Plasma Protein of Rats Fed Rat Chow, Supplemented and Nonsupplemented Cakes

Rat groups	% avocado pear pulp supplementation	7 days before feeding (mg/dL)	14 days after feeding (mg/dL)	% difference
RAC₁	—	51.00^a ± 5.92	61.60^a ± 6.54	20.78↑
AV	0	69.00^c ± 2.24	73.20^b ± 6.46	6.09↑
AVC₁	10	65.00^bc ± 5.00	69.00^ab ± 3.39	6.15↑
AVC₃	30	64.20^bc ± 7.09	68.20^ab ± 6.98	6.23↑
AVC₅	50	60.60^b ± 2.88	64.80^a ± 4.87	6.93↑

Data are mean ± SEM values; n = five; means with different superscripts in the same column differ significantly by Duncan New Multiple Range Test (P < .05). Arrow up means “increase in % difference”. RAC₁, rat chow (poultry growers mash); AV, nonsupplemented cake; AVC₁, cake supplemented with 10% avocado par pulp; AVC₃, cake supplemented with 30% avocado pear pulp; AVC₅, cake supplemented with 50% avocado pear pulp. $% d i f f e r e n c e = \frac{P l a s m a p r o t e i n a f t e r f e e d i n g - p l a s m a p r o t e i n b e f o r e f e e d i n g}{P l a s m a p r o t e i n b e f o r e f e e d i n g} \times 100 %$ .

Discussion

The observed differences in food intake could be attributed to unfavorable aroma or taste of the cake supplemented with avocado pear pulp. Palatability, source of nitrogen and essential amino acid profile of food can influence the food intake¹⁵ or physiological state of the animals.

The increase in the body weight among rats fed supplemented cakes could be due to effect of heat on β-sitosterol, which reduces weight by controlling excessive food consumption.³ This could be responsible for the weight gain, despite the irregular food intake. The comparable increase in weight of the rats fed supplemented cakes could also be attributed to changes in lipids due to baking.

Increase in cholesterol observed in this study was contrary to the report of Grant¹⁶ and Pieterse et al.,¹⁷ which reported reduction in serum TC in half of his subjects, while diabetic or very hypercholestrolemic had neutral effect and did not gain weight after consuming 0.5–1.5 avocados daily. Heating at 180°C of edible fat increases saturated trans-fatty acids and decreases Cis-unsaturated fatty acid.¹⁸ Vegetable oils heated at high temperature could cause degradation and oxidation of compounds in oils, thereby producing substances that might have detrimental effects on health.¹⁹ Navasimhamurthy and Raina²⁰ observed higher plasma cholesterol levels, lower HDL-C, and increased LDL-C and VLDL-C in rats fed heated vegetable oils. Hyperlipidemic induced rats fed 25% raw avocado pear fruit pulp improved body weight gain, feed intake, and serum lipid profile, and liver and kidney functions.²¹ These reports indicate that avocado fruit pulp is better consumed in raw form than when heated. Heat applied during baking seems to have changed the structure of monounsaturated and polyunsaturated fatty acids in avocado pear pulp to trans-fatty acids since nonsupplemented cake (0% avocado or 100% margarine) had similar increase in cholesterol and TG with avocado supplemented cakes. Despite the increases in TC and TG, all the avocado supplemented cakes reduced the LDL-C and increased HDL-C, hence lowering the risk of developing coronary heart disease.

High levels of TGs in the blood due to inhibition of glucose utilization and oxidation contribute to the risks of cardiovascular diseases because it is equivalent to TC and people with high TGs do have high TC, LDL, and HDL levels.²² TGs are not only from dietary fats but are also synthesized in the liver from excess carbohydrate not used for production of energy.²³

The study recorded a significant (P < .05) decrease in the percentage difference of the LDL in all the test groups as supplementation level increases. Lipoproteins, specific protein particles, transport cholesterol all over the body.²⁴ Avocado enriched diets improved blood lipid profiles by lowering LDL-C and TGs and increasing HDL-C compared to high carbohydrate diets²⁵ or other diets without avocado in both normolipidemic and hypercholesterolemic subjects. LDL carries cholesterol made from the liver and other sources to cells. Liver is the main organ responsible for maintaining cholesterol balance in the whole body and in regulating the levels of circulating lipoprotein cholesterol.²⁶ Increased LDLs are associated with an increased risk of atherosclerosis and coronary heart disease.²⁷ Hyperlipidemia, progression of atherosclerosis, and cardiovascular diseases have been documented to be due to increased levels of LDLs.^15,28 Reducing dietary fat is recommended to reduce total blood cholesterol and LDL in adults.²⁹

All the five groups had higher increases in serum HDL concentration with the group fed 50% supplemented avocado pear pulp cake having the highest percentage difference (76.79%). The intake of cakes supplemented with avocado pear pulp showed an increase in serum TC and HDL-C in all the test groups with greater increase seen in the group fed cake supplemented with 50% avocado pear pulp. This could be due to the hypothetical fact that, although all test groups received the same quantity of cake, each quantity given had varying content of avocado pear pulp in them. The increased levels of HDL-C and reduced LDL-C confirm that the cakes had a positive effect on cardiovascular diseases and will therefore act to reduce the incidences arising from cardiovascular diseases. Kontush and Chapman²⁷ reported that for any 0.026 mM increase in HDL-C, there is a 3% decrease in the risk of mortality from cardiovascular disease by removing cholesterol from cells and its excretion from the body. The greater increase in HDL in the group fed 50% supplemented avocado pear pulp cake suggests being very effective in reducing the risks of cardiovascular diseases in rats and may be used in humans. The increases in HDL-C observed in the avocado pear supplemented cakes may be attributed to the effect of heat on β-sitosterol that helps in reducing cholesterol and MUFAs, which have ability to reduce LDL-C and raise HDL-C.¹ β-sitosterol inhibits intestinal absorption of cholesterol and decreases hepatic cholesterol production by acting on total plasma cholesterol and LDL-C without harm on HDL-C and blood TGs.³⁰ Studies have shown that elevated HDL-C tends to prevent development of atherosclerosis and its decrease is related to high risk of cardiovascular diseases.³¹

There were increases in the plasma protein levels of all the test groups. It was observed that the higher the supplementation, the higher the increase in percentage difference of plasma protein. The group of rats fed cake supplemented with 50% avocado pear pulp had the highest percentage. This could be attributed to the increased protein and fat content of avocado pear pulps. Plasma proteins serve many different functions, including transport of lipids, hormones, vitamins, and minerals in the circulatory system.

Conclusion

The groups fed 30% and 50% supplemented cakes had increase in weight gain, despite decrease in food intake. The increment in cholesterol and TG did not elevate LDL-C or decrease HDL-C, indicating that consumption of these supplemented cakes may not have any detrimental effect on health. The study revealed that cake supplemented with graded levels of avocado pear pulp had high potentials in increasing HDL-C and decreasing LDL-C. Cake supplemented with 50% avocado pear pulp had a better overall supplemental effect. It is therefore deduced that cake supplemented with avocado pear pulp can be of use in maintaining cardiovascular health, and in prevention and management of cardiovascular diseases. Further study should elucidate the effect of baking temperature, type of fats, and carbohydrates in avocado pulp supplemented cakes that may have caused slight increment in TC and TG instead of lowering them.

Footnotes

Author Disclosure Statement

No competing financial interests exist.

Funding Information

The research work was jointly funded by the authors.

References

Fahri

: Avocdos Nutrilife: Nutrition and lifestyle. www.nutrilifeclinic.com (accessed 27 April, 2019)

Ware

, Webberley

: Avocados: Health

Benefits

, Nutritional

Information

. www.hassavocado.com/efa.html. (accessed 18 April 2016).

Bergh

: The avocado and human nutrition.1. Some human health aspects of the avocado. Proc of Second World Avocado Congress, 1992; 25–35.

Bjarnadottir

: 2015. Avocado 101: Nutrition facts and Health benefits. https://authoritynutrition.com (accessed 17 May 2016).

Onoja

, Dibua

UME

, Eze

: Effets of fermentation on the Nutrient composition, energy, and sensory properties of wheat- based doughnuts supplemented with blends of some Nigerian indigenous food crops. Glob J Pure App Sci, 2011; 17:329–334.

Mastromatteo

, Danza

, Lacce

, Spinelli

, Lampignano

, Laverse

, et al.: Effect of durum wheat varieties on bread quality. Intl J Food Sci Tech, 2013; 49:72–81.

Hussein

, El-Beltagy

, Gaafar

: Production and quality evaluation of low caloric cake. Am J Food Tech, 2011; 6:827–834.

Mahmoud

, El-Shatanovi

GAA

, Asad

EAM

, Abdel-Khalek

: Using of dietary fiber and sugar-fat substitution in the production of low calorie cakes. Ann Agric Sci, 2002; 47:255–271.

Kalinga

, Mishra

: Rheological and physical properties of low fat cakes produced by addition of cereal and β-glucan concentrate. J Food Process Preserv, 2009; 33:384–400.

10.

Kim

HYL

, Yeom

, Lim

: Replacement of shortening in yellow layer cakes by corn dextrin. Cereal Chem, 2001; 78:267–271.

11.

Siró

, Kápolna

, Lugasi

: Functional food. Product development, marketing and consumer acceptance-A review. Appetite, 2008; 51:456–467.

12.

Campbell

, Foskett

, Rippington

, Paskins

: Practical Cookery for Level 2 AVQs and Apprenticeship. United Kingdom: Hodder Education, 2012, 12th ed. p. 567.

13.

Ochei

, Kolhatkar

: Medical Laboratory Science, Theory and Practices. New York: Tata McGraw-Hill Publishing Company Limited, 2008, pp. 311–347.

14.

Nwanjo

, and Oze

: Changes in serum lipid profiles and heart rate in ratstreated with aqueous garlic extract. Internet J Nutr Wellness, 2006; 4:1–6.

15.

Rowland

: Food or fluid restriction in common laboratory animals: Balancing welfare considerations with scientific inquiry. Comp Med, 2009; 57:149–160.

16.

Grant

: Influence of avocados on serum cholesterol. Proc Soc Exp Biol Med, 1960; 104:45–47.

17.

Pieterse

, Jerling

, Oosthuizen

: Substitution of high monounsaturated fatty acid avocado for mixed dietary fats during an energy restricted diet: Effects on weight loss, serum lipids, fibrinogen, and vascular function. Nutrition, 2005; 21:67–75.

18.

Bhardwaj

, Passi

, Misra

, Pant

, Anwar

, Pandey

, Kardam

: Effect of heating/re-heating of fats as used by Asian Indians on transfatty acid formation. Food Chem, 2016; 212:663–670.

19.

Soupas

, Juntunen

, Saynajoki

, Lampi

, Purone

: GC- MS method for characterization and quantification of sitostanol oxidation product. J Am Oil Chem Soc, 2004; 81:135–141.

20.

Narasimhanmurthy

, Raina

: Long term feed effects of heated fried oils on lipoprotein and lipids in rats. Mol Cell Biochem, 1999; 195:143–153.

21.

Alghamdi

, Yousef

: Effect of avocado on serum lipids of hyperlipidemicrats. Curr Sci Int, 2017; 6:199–207.

22.

American Heart Association: What cholesterol levels mean www.heart.org/HEARTORG/Conditions/AboutCholesterol/What-Your-Cholesterol-Levels-Mean_UCM_305562_Article.jsp#.XOVPQ9gkrIV (accessed May 23, 2019 )

23.

Wilson

TAC

, Meservev

, Nicolosi

: Soy lecithin reduces plasma lipoprotein cholesterol and early atherogenesis in hypercholesterolaemic monkeys and hamsters: Beyond linoleate. Atherosclerosis, 1998; 140:147–153.

24.

Carmena

, Duriez

, Fruchart

: Atherogenic lipoprotein particles in atherosclerosis. Circ, 2004; 109(Suppl 111):2–7.

25.

Dreher

, Davenport

: Hass avocado composition and potential health effects. Critic Rev Food Sci Nutr, 2013; 53:738–750.

26.

Dietschy

, Turley

, Speady

: Role of liver in the maintenance of cholesterol and low density lipoprotein in different abnormal species, including human. J Lipid Res, 1993; 34:1637–1659.

27.

Kontush

, Chapman

: Antiatherogenic small dense HDL-guardian angel of the arterial wall?. Nat Clin Pract Cardiovasc Med, 2006; 3:144–153.

28.

Hooper

, Summerbell

, Thompson

, Sills

, Roberts

, Moore

, Smith

: Reduced or modified dietary fat for preventing cardiovascular diseases. Cochrane Database Sys Rev, 2012; 5:CD002137.

29.

Igweh

, Nwaghia

CIU

, Okaro

: The effects of menopause on the serum lipid profile of normal females of south east Nigeria. Nig Phy Sci, 2005; 20:48–53.

30.

Brufau

, Canela

, Rafecas

: Phytosterols: Physiologic and metabolic aspects related to cholesterol- lowering properties. Nutr Res, 2008; 28:217–225.

31.

Mendez

, Franlein

, Gahegan

: Simple manual method for determination of serum triglycerides. Chemistry, 1975; 21:760–770.