Proximate and Sensory Evaluation of Different Zobo-Moringa Blends Packaged in Tea Bags

Different blends of Roselle calyx and Moringa leaves (90:10%. 80:20%, 70:30%, and 50:50% respectively) were used in processing the novel instant “Zobo-moringa mix” by drying, grinding and mixing of Zobo calyx, moringa leaves, ginger, cloves and orange flavour. Various recipes were formulated using linear programming, after which sensory evaluation was carried out to obtain an acceptable formula. Dried Moringa leaves were added at different proportion by varying the amount of Zobo calyx used. All samples were packaged in teabags. Proximate analysis was carried out on the samples. The results of the proximate analysis showed that the proximate composition of the samples was significantly higher (P < 0.05) in protein and it increases as the proportion of Moringa increases from 2.325% to 28.05%. For the crude fiber, there was a decrease in its composition from 14.00% to 5.70% as the proportion of Moringa increases. It is significantly low in carbohydrate from 59.98% to 29.62% as the proportion of Moringa increases. The results of the sensory evaluation of the samples showed that the samples into which Moringa were incorporated were generally more accepted than the conventional Zobo sample (control).

fura da nunu (fermented skim milk with millet dough), Zobo (extracts of calyx of Hibiscus sabdariffa), wara (cheese whey), etc. Zobo drink isa traditional non-alcoholic beverage which is consumed in most part of Nigeria, mostly in northern part of Nigeria (Osuntogun, 2004). The zobo drink is a red liquid drink and taste like fruit punch, served as a fair source of vitamin A, riboflavin, niacin, calcium and iron (Qi et al., 2005), and is low in sugar content. It is extracted from the dried reddish purple calyces of the plant Hibiscus sabdriffa (Scott, 2003). Hibiscus sabdariffa (Roselle) is an annual herb that is grown in the tropics and it is widely cultivated in Nigeria mainly in the Northeastern and Middle-belt regions (Bolade et al., 2009;Nwafor & Ikenebomeh, 2009;Yadong et al., 2005;and Omemu et al., 2006). Moringa Leaf powder is an excellent nutritional supplement and can be added to any dish (Fuglie, 2001).The shelf life of any drink is dependent on the packaging material used; the use of teabags proves to be a means of preventing loss of quality of products, inhibitmicrobial contamination, preventing discolouration of the drink, and above all permitting large-scale production and preservation of the beverage for a longer period with maximum retention of nutritive value (Vermeiren et al., 1999).
The production process of Hibiscus sabdariffa (zobo) drink has not been mechanized nor standardized and the shelf life of the drink is less than two days due to microbial attack, making it loose its physico-chemical and organoleptic quality (Nwafor & Ikenebomeh, 2009;and Olawale, 2011). This work is therefore aimed at producing instant "zobo-moringa mix" which can keep longer and can be prepared easily by extraction using hot water.

Sample Collection
The dried zobo calyx, moringa leaves, sweetener, flavours and other ingredient used in this work were bought from the main market (Eke-onuwa) in Owerri and transported to FUTO where the production and analysis of the product was carried out. The materials were procured in its wholesome condition and reasonable quantities.

Processing of Hibiscus Sabdariffa Calyxes
The Hibiscus sabdariffa calyces were obtained and the dirt was sorted out by winnowing. It was mixed and dried in the oven to further reduce the moisture content. The dried calyces were then crushed to a mesh size of 200 micron and sieved. These tea size particles were then stored in an air tight vessel.

Processing of Moringaoliefera Leaves Powder
Leaves were dried at room temperature inside a room protected from light (to prevent the loss of vitamins) and protected from dust and pests (to prevent contamination). Dried leaves were made into powder using a burr mills (motor driven). The powder is sifted to remove any remaining stems. It was stored in airtight containers protected from heat, humidity and light.

Processing of Ginger and Cloves
The ginger bulbs were dried under sunlight and it was grounded into powder using an attrition mill.
The cloves were also grounded into powder using the attrition mill. The entire grounded ingredients were stored in an air tight container, in other to prevent them from losing their volatile components.

Recipe Formulation
Linear programming is a mathematical technique used in computer simulations to find the best possible solution in allocating limited resources or ingredient to achieve maximum profit and cost. It can be applied to a wide variety of fields of study and has proved useful in planning, routing, scheduling, assignment and designing, such as transportation or manufacturing industries. This model was used to calculate the formulation needed to obtain the desired product. Five recipes were obtained and these were the result:

Proximate Analysis
The proximate analysis was carried out on the Roselle-Moringa blend. They were analyzed chemically according to the official methods of analysis described by Association of Official Analytical Chemists (A.O.A.C, 1990).

Determination of Moisture Content
The moisture content was determined by weighing out 2 g of each of the sample into a dry petri dish of a known mass, charged into the oven at temperature of 105 o C and heated for 3 hours. The dried samples were then withdrawn from the oven and placed in a desiccator to cool. They were weighed using the analyticalbalance (electronic) and the whole process was repeated until a constant mass was obtained. The difference in mass as percentage (% moisture) was calculated thus:

%Moisture =
Where; M 1 = mass of dish M 2 = mass of dish + sample before drying M 3 = mass of dish + sample after drying.

Determination of Crude Fat
A soxhlet extraction unit was setup with a reflux condenser. A small round bottom flask was weighed after washing and drying, and half filled with light petroleum ether (Boiling point 40-60 o C) and fixed into the unit. Two (2) grams of each of the samples were wrapped with a Whitman filter paper and gradually lowered into the thimble which was fitted into the cleaned, dried and weighed round bottom flask containing 120 ml of petroleum ether. Samples were slowly heated with heating mantle for 5 hours. Refluxed petroleum ether was recovered and the flask containing the fat and oil was cooled in the desiccator and reweighed after drying. By difference, the mass of oil extracted was determined and thus expressed as percentage; % CrudeFat =

Determination of Crude Protein
The Keldjhal method as described by AOAC (1990) was used. The total nitrogen was determined and 6.25 were used to multiply to obtain the protein. Two (2)  solution. Titration was done from green to a deep red end point. A reagent blank was determined as discussed above but without the sample. The protein content was calculated.

Determination of Crude Fiber
Two (2)

Determination of Ash Content
Five (5) grams of the sample was put in a crucible, ignited and tarred. The crucible was placed in a drying oven at 100°C for 4 hours and then transferred to a cool muffle furnace as the temperature was increased to 550°C ± 5°C. The temperature was maintained for 8 hours until white ash was obtained.
The crucible was placed in a desiccator with the aid of thongs, to cool and then weight was determined.
The percentage (%) ash was calculated as thus; % Ash=

Determination of Carbohydrate
The carbohydrate content was determined by the difference method.

Sensory Evaluation
Sensory evaluation was carried out using an 18-man panelist to assess the organoleptic attributes of the Roselle-Moringa blend samples. The organoleptic attributes assessed were; colour, taste, aroma, mouth-feel and general acceptability. The panelists were selected randomly from the staff and students of Federal University of Technology, Owerri. The sensory evaluation was conducted using a 9-point hedonic scale as described by Ihekoronye and Ngoddy (1985), where scoring scale ranges from 9 = liked extremely to 1 = disliked extremely.

Statistical Analysis
The results of the proximate analyses and the sensory evaluation were computed and a one-way Analysis of Variance (ANOVA) and Fishers Least Significant Difference (LSD) was used to establish the significance differences among the value at 0.05 level of confidence. The statistical analysis was computed using the program, Minitab 16.2.1 (2010).

Recipe Formulation of Instant Zobo Drink
Five formulas of instant "zobo mix" ( meant the panelists were indifferent to the product. The acceptance level of Formula 1 was significantly different from other formulations produced. The sensory analysis showed Formula 3 to be the best in terms of taste, aroma, mouth-feel and general acceptance. It lagged behind Formula 2, Formula 4 and Formulae 5 in terms of colour but was still deemed similar to them. Formula 1 was the least appreciated of the lot in all criteria with a similarity only in colour and in aroma to any of the products.
The tabular representation of the results of the sensory evaluation of the various recipes done by the 18-man panelists is shown in Table 3, while the optimum formula obtained from linear programming is given in Table 4. Orange flavor 4.60

Proximate Result of the Zobo-Moringa Mix
The tabular representation of the results of the proximate analysis carried out on the zobo-moringa mix for the different samples is shown in table 3.2. From the result of the proximate analysis (See Table 5 for codes) For the Fat analysis, it was observed that ZCON (6.30 ± 0.02) (control) is significantly different (P < 0.05) from the samples that were mixed (i.e., ZM90, ZM80, ZM70, and ZM50). Also there was no significant difference (P > 0.05) between ZM90 (8.50 ± 0.02) and ZM80 (11.40 ± 0.01), while ZM70 (14.50 ± 0.01) and ZM50 (17.10 ± 0.01) was significantly different (P < 0.05

Sensory Evaluation on the Samples (Zobo-Moringa Blend)
The results of the sensory evaluation are shown in Table 5. There was no significant difference (P < 0.05), in colour among the samples, but there was a significant difference between the four samples and control. The highest value of7.90 was obtained from sample ZCON, while the lowest value was obtained from the ZM50. Generally, the value of the ZCON were greater than other samples, this may be as a result green pigmentation of the chlorophyll present in the Moringa leaves which makes the colour brighter and sharper. For the Aroma, there was a significant difference (P < 0.05), between ZM50 and ZCON, ZM90 and ZM50, but there was no significant difference (P < 0.05), between ZM70 and ZM80, ZM70 and ZM50, ZM70 and ZM90, ZM80 and ZM90, ZM80 and ZCON. For Taste, there was no significant difference (P < 0.05) among the samples, but there was a significant difference between the samples and the control. For the mouth feel, there was no significant difference between sample ZM90, ZM80 and ZM50 but there was a significant difference (P < 0.05), between samples ZM50, ZM70, ZM80, ZM90 and ZCON; there was also a significant difference between ZM80 and ZCON. for the general acceptance there was no significant difference among the samples, also there was no significant difference (P < 0.05) between the samples and the control, this may be attributed to the same recipe (ginger, close and flavour) used for the samples, also the packaging in teabags makes the products more acceptable to the panelists.

Conclusion
The findings from this work have shown that an acceptable instant "zobo-moringa" mix could be formulated. Interestingly, a formular for that was developed using linear programming. This is very important in industrial production of instant "zobo-moringa" mix.