Nutritional Potentials of Rhynchophorus phoenicis (Raphia palm weevil): Implications for Food Security

 

A. J.Chinweuba1, I. E. Otuokere2, M.C. Opara3 and G.U. Okafor4

1Department of Chemistry, Anambra State University, Uli

2Department of Chemistry, Michael Okpara University of Agriculture, Umudike

3Faculty of Education, Anambra State University, Uli.

4Department of Pure and Industrial Chemistry, Nnamdi Azikiwe University, Awka.

*Corresponding Author E-mail: tosmanbaba@yahoo.com

 

ABSTRACT:

Proximate and chemical analysis were carried out on the Early Larva (EL) and Late Larva (LL) stages of Raphia palm weevil (Rhynchophorus Phoenicis) to ascertain its nutrition potentials. The Late Larva stage had the highest protein content of 10.50% while 9.10% was recorded for early larva stage. All other essential classes of food and amino acids were detected in varying amounts. The values derived for macro elements such as calcium, potassium and iron were (0.28 ± 0.01mg/100g), (455.00 ± 21.00mg/100g) and (6.50 ± 0.40mg/100g) respectively for Early Larva stage; (0.27 ± 0.01mg/100g), (457.50 ± 10.61mg/100g) and (6.00 ± 1.10mg/100g) respectively for Late Larva stage. The results of the mineral contents showed that nutritive contents of Phynchophorus phoenicis at LL stage are higher than EL stage. The study attests that both stages of the insect larva could form a base for food security by providing nutritious food to meet people dietary needs for active and healthy life.

 

KEYWORDS: Food security, Phynchophorus phoenicis, malnutrition, macro elements.

 


 

INTRODUCTION:

Edible insects are important sources of diet to some rural dwellers in many States of Nigeria. Among the most important orders of insects consumed in Nigeria are Cleoptra, Hymenoptra, Isoptra, and Odonata1. The larva of Raphina palm (palm wine tree) weevil known, as “edible worm is a delicacy in many parts of Nigeria among those who strongly believe that it has medicinal properties1. On the contrary, in some areas where it is in abundance, many people do not consume the larva either because they are unaware of its nutritional properties or for some superstitious belief that it ridiculous to eat larva. The issue of malnutrition and food security is a major source of concern and estimates have shown that 36 million people have died of hunger and diseases due to deficiencies in micronutrients 2,3. Hunger and malnutrition are the single greatest threats to the world’s public health and malnutrition is by far the biggest contributor to child mortality 4,5.  Malnutrition increases the risk of infection and infections disease. Lack of sufficient nutrients can weaken immune system and invite infectious diseases 5.

 

Against this background, it becomes imperative to analyze the potentiality of Phynchophorus phoenicis for nutrients. It is an insect that grows in abundance in palm wine trees, it has very low cost effectiveness and by implication can assuage the problems of malnutrition and diseases caused as a result of deficiency in macronutrients and micronutrients.

 

MATERIALS AND METHODS:

Life larva of Raphia palm weevil (R. Phoenicis) was purchased at Ose Ekeke, a fishing terminal at the bank of Ose Ekeke river, Akwu-ukwu in Anambra State Nigeria. The larvae were classified into early and late stages (EL and LL) based on head capsule measurement, weight, body length, body width and circumference (Table 1).

 

The larvae were transported to the laboratory in their moist feed of Raphia palm pith in a well ventilated container within eight hours of collection. The larvae were washed and killed by asphyxiating in the freezer for 48 hours.

Lipid from the larva was extracted by Bligh method6. The moisture and ash contents were estimated by AOCS method7.

 

The mineral compounds of R. Phoenicis were determined using Alpha 4 Atomic Absorption Spectrophotometer. Sodium and potassium were estimated by Corning 405 Flame Photometer. The amino acid profile of the larva stages was determined by AOCS mehtod7 in a Technicon Sequetial Multi Sample Amino Acid Analyzer (TSM). Fatty acid methyl ester (FAME) was prepared using AOCS method 7 while the GIC used was a Pye Unicam Series 104 GCD equipped with flame ionization detector (F.I.D) and connected to a Hitachi model 056 recorder. The stationary phase comprises 10% Polyethylene Glycol Adipate (PEGA) and silanised  chromosorb W(100-120 mesh) packed  in a 1.5 X 4mm glass column of length 5ft. Crude protein was estimated by using calorimetric method 8.

 

RESULTS AND DISCUSSIONS:

The dimensions of the larva used have been recorded in Table 1.

Table 1: Dimension of the Larva Stage (EL and LL) of R. phoenicis used.

Samples

Weight (g)

Body Length (cm)

Body width (cm)

Head region (cm)

Circumference (cm)

Early Stage

2.29± 0.14

2.54±  0.04

0.77 ± 0.04

0.65 ± 0.04

3.07 ± 0.06

Late Stage

8.14 ±  0.14

4.61 ± 0.06

2.05 ± 0.04

1.10 ± 0.01

5.47 ± 0.18

 

Table 2: Proximate composition of larva stages of R. phoenicis (%)

Nutrients

Late Larva Stage

Early Larva Stage

Moisture

42.30 ± 2.00

43.30 ± 2.00

Lipid

25.40 ± 1.00

24.20 ± 0.20

Protein

10.50 ± 0.01

9.10 ± 0.01

Ash

2.33 ± 0.23

2.37 ± 0.15

Fibre content

6.00 ± 0.01

5.80 ± 0.15

Carbohydrate

12.00 ± 0.01

13.00 ± 0.02

 

Table 3: Fatty acid composition of larva stages of R. phoenicis (% fatty acid)

Fatty Acids

Late Larva Stage

Early Larva Stage

Lauric

0.02  ± 0.03

0.03  ± 0.01

Myristic

3.20  ± 0.12

2.30  ± 0.10

Palmitic

32..40  ± 0.58

25.40  ± 0.45

Palmitoleic

3.30  ± 0.20

2.20  ± 0.20

Stearic

3.10  ± 0.13

3.10  ± 0.50

Oleic

40.10  ± 0.72

29.10  ± 0.50

Linoleic

12.00  ± 0.10

12.00  ± 0.20

Linodemic

3.40  ± 010

3.30  ± 0.10

Arachidomic

1.20  ± 0.03

1.20  ± 0.02

 

Table 4: Amino acid composition of larva stages of R. phoenicis (g/100g protein)

Amino Acid

Late Larva Stage

Early Larva Stage

Lysine

3.98

3.70

Histodine

3.20

3.00

Arguine

5.10

5.00

Aspartic acid

7.00

7.00

Threonine

3.00

3.00

Serine

11.50

11.00

Glutamic acid

2.00

2.00

Proline

3.02

3.01

Glycine

2.50

2.40

Alanine

2.90

2.80

Cysteine

3.00

3.01

Valine

2.20

2.00

Methionine

2.70

2.50

Isoleucine

2.05

2.00

Leucine

3.20

3.10

Tyrosine

6.00

5.80

Phenylamine

2.00

2.00

Tryptophan

2.40

2.30

Table 5: Mineral composition of larva stages of R. phoenicis (mg/100g)

Elements

Late Larva Stage

Early Larva Stage

Fe

6.00  ± 1.10

6.50  ± 3.00

Zn

10.00  ± 0.20

8.00  ± 1.80

Mn

1.16  ± 0.07

1.12  ± 0.20

Pb

0.10  ± 0.01

0.10  ± 0.01

Ca

20.00  ± 1.00

19.50  ± 1.00

Na

65.69  ± 2.00

62.00  ± 2.00

K

457.50  ± 13.00

455.00  ± 11.00

 

The moisture contents values (Table 2) for late larva stage and early larva stage (42.30 ± 2.00) and (43.30 ± 2.00 respectively, compare well with the conventional animal foods (beef, chicken and fish) which have a moisture content ranging from 40-70% 9. This is an indication that most essential nutrients in the larva will be in solution and in forms that are easily available to the body when consumed. The larva with high lipid contents of (25.40 ± 1.00) and (24.20 ± 0.20) for late and early larva stages respectively, indicate that 100g sample of the larva will meet the caloric requirement in developing 10. A relatively high ash content observed (Table 3) for both stages of the larva compared well with the reported values for meats and poultry 9. High protein values were also obtained; therefore consuming the larva of this insect could help in combating protein deficiency. Insects are known to be rich sources of various macro and microelements 10. Results of the mineral composition (Table 5) of the specimen show that consuming 100g of the specimen will meet the RDA for iron, zinc and magnesium in developing countries.

 

The mineral composition determined can particularly be useful for pregnant and lactating women. The presence of the essential amino acids like lysine, leucine and threonine in substantial amounts (Table 4) further points to the nutritive value of Rhynchophorus phoenicis. The quality of protein in food is determined by its essential amino acid contents, compared with rice, cassava and maize, the larva contains more essential amino acids.

 

CONCLUSION:

Proximate and chemical analysis have been were carried out on the Early Larva (EL) and Late Larva (LL) stages of Raphia palm weevil (Rhynchophorus Phoenicis) to ascertain its nutrition potentials. The Larva stage had  high protein content.  All other essential classes of food and amino acids have been detected in varying amounts.  The results of the mineral contents showed that nutritive contents of Phynchophorus phoenicis at LL stage are higher than EL stage. Consumption of Rhynchophorus phoenicis could serve as a cheaper source of essential nutrients in countries where it is found. It can also be processed and packaged for other-sahara countries as potential tools for reducing of malnutrition and ameliorate the problem of food insecurity.  Both stages of the insect larva could form a base for food security by providing nutritious food to meet people dietary needs for active and healthy life.

 

REFERENCES:

1.       Ekpo KE. Biochemical investigation of the nutritional value and toxicological safety of entomophagy in southern Nigeria. Unpublished Ph.D thesis, Ambrose Ali university, 2003; 23 – 24.

2.       Http://en.wikipedia.org/wiki/Malnutrition, Retrieved on 25th March, 2010.

3.       Http://www.absoluteastronomy.com/topics/Malnutrition, Retrieved on 25th March, 2010.

4.       Alberto G, Francesco S. Child Malnutrition and Mortality in Developing Countries: Evidence from a Cross-Country Analysis, Nutritional Society Journal, 2007; 2(3): 12 – 17.

5.       Alva S, Kleinau E, Rowan K and Teller C. Malnutrition and Child Mortality in Sub-Sahara African: A Growing Gap? Paper Submitted to the Annual Meetings of the Population Association of America, New Orleans. 2008; 23 – 28.

6.       Bligh  EG and Dyner NJ. A rapid method for total lipid. Can J. Biochem. Physiol. 1997; 37: 911-917.

7.       American Oil Chemists Society (AOCS), Sampling and analysis of commercial fats and oils, Official method of analysis of American oil Chemists Society, 1960; 801-855.

8.       Williams PC. Determination of Crude (Total) protein using the calorimetric method, Analyst. 2009; 84: 281-283.

9.       Watt BK and Merril AL. Consumption of foods – Raw, Processed and Prepared. US Department of Agriculture Handbook, 1963; 8:1-189.

10.     Davidson S, Pasmore R and Brock JF. Human Nutrition and Dietetics, 5th edition  English  Language Book Society and Churchill Livingstone, 1073; 77.


 

 


 

 

Received on 18.03.2010        Modified on 08.09.2010

Accepted on 28.11.2010        © AJRC All right reserved

Asian J. Research Chem.  4(3): March 2011; Page 452-454