Food Science and Technology Project Topics

Proximate and Consumer Acceptability of Cookies Produced From Wheat-sweet Potato Composite Flour

Proximate and Consumer Acceptability of Cookies Produced From Wheat-sweet Potato Composite Flour

Proximate and Consumer Acceptability of Cookies Produced From Wheat-sweet Potato Composite Flour

Chapter One

Aim and Objectives

Therefore the aim and objective of this study is to determine the proximate and consumer acceptability of cookies produced from wheat and sweet potato composite flour.



Wheat (TriticumAestivum)

Wheat, a cereal grass of the Gramineae (Poaceae) family and of the genus Triticum and its edible grain, is the world’s largest cereal-grass crop. It has been a food crop for mankind since the beginning of agriculture. The Middle East is probably the area of origin, and it was spread throughout Europe not later than the Stone Era. Historians believed that it has been growing since Paleolithic times and cultivated since 6000 years. Its status as a staple is second only to rice. The reason for its popularity is that, unlike other cereals, wheat contains a high amount of gluten, the protein that provides the elasticity necessary for excellent bread making. Although over 30,000 varieties of wheat exist, the two major types are bread wheat and durum wheat (McFadden and Sears, 2006).

Global production of wheat is approximately 600 million tons; with international trade approximately 100 million tons annually. Wheat is Asia’s second most important staple and has been growing much faster than rice. Wheat provides one-fifth of total developing country food supply, up from 15 % in the early 1970s. In 1992-94, developing countries accounted for 45 % of world wheat production (551 million tons) and 46 % of world wheat area (219 million hac).

 Pharmacognosy and Phytopharmacology of Wheat Grass

            Taxonomical Details

Kingdom:                                Plantae – Plants

Subkingdom:                           Tracheobionta – Vascular plants

Superdivision:                         Spermatophyta – Seed plants

Division:                                  Magnoliophyta – Flowering plants

Class:                                       Liliopsida – Monocotyledons

Subclass:                                 Commelinidae

Order:                                      Cyperales

Family:                                    Poaceae – Grass family

Genus:                                     Triticum L. – wheat

Species:                                   TriticumAestivum

Sources: McFadden and Sears (2006)

The wheat plant is an annual food grass. It is mainly grown as a winter annual in milder climates, with seeding in the fall and harvest from June through August depending on the length of the winter. In areas with rigorous winter climates, it is mainly spring seeded. Planting is as early as soil can be worked, and harvest is in late summer and early fall. In early growth stages, the wheat plant consists of a much-compressed stem or crown and numerous narrowly linear or linear-lanceolate leaves. Leaves are mainly near glabrous. Buds in the leaf axils below the soil surface grow into lateral branches termed tillers. From both the main crown and the tillers, elongated stems develop later and terminate in a spike or head in which the flowers, and finally the seeds or grains develop. Stems of wheat reach from 18 inches to 4 or more feet in height depending on kind and growing conditions (Talbert et al., 1998).

Different species of wheat  

Wheat species differ from one another both morphologically and genetically. Triticum species can be placed in three groups, according to whether their body cells contain 14, 28 or 42 chromosomes. The basic haploid number being 7, these groups are described as Diploid, Tetraploid and Hexaploid respectively.

Diploid Species: Diploid species include Triticumboeoticum (Wild Eincorn – most ancient variety of wheat) and Triticummonococcum (Eincorn). Triticumboeoticum was growing in Southwestern Asia before the advent of agriculture. Triticummonococcum is now grown to a limited extent in the mountainous region of Yugoslavia, Asia Minor and North Africa. Diploid species can be readily crossed to yield Tetraploid group.

Tetraploid Species: Tetraploid species include Triticumdicoccum (Emmer wheat, local variety -DDK) and Triticum durum (Durum wheat or Macaroni wheat, local varieties – Bansi, Kathia, Khandwa, Raj 1555). Triticumdicoccum is one of the most ancient of cultivated cereals. It was formerly grown in the United States for feed on a limited acreage but now has substantially disappeared from cultivation. It is grown to a limited extent in the nilgiri hills and the neighboring areas and is preferred for the preparation of suji or rawa. Triticum durum, next important species to Triticumaestivum, is used mainly for the manufacture of semolina which is made into macaroni, spaghetti and related products. Although high in gluten, Triticum durum is not good for baking. Instead, it is often ground into semolina, the basis for excellent pasta, such as spaghetti and macaroni. It is grown to a considerable extent in parts of Gujarat and central peninsular India. It is preferred for preparation of vermicelli or sewian. When crossed with Diploid species, Tetraploid species yield Hexaploid group.

Hexaploid Species: Hexaploid species include Triticumaestivum (common wheat, bread wheat, local varieties – Sharbati, Lalkanak, Lok1, GW 273). Triticumaestivum is the most evolved and widely cultivated of all wheat species. It is high in protein (10-17 %) and yields flour rich in gluten, making it particularly suitable for yeast breads. It is also preferred for the preparation of biscuits, cake and pastry manufacture. In India, Triticumaestivum is the most widely grown wheat species.





Sweet potato roots, wheat flour, groundnut seeds and all other ingredients (sugar, fat, flavoring, baking powder, eggs etc) used for the cookies production were obtained from a local market in Owo, Ondo State, Nigeria.


Preparation of Sweet Potato Flour

The sweet potatoes tubers were purchased from “OjaOba” in Owo and the potato skin were peeled off from the tuber, the edible portion of the sweet potatoes were washed in clean tap water, before they were sliced into pieces and sun dried. After two weeks of sun drying, the dried potatoes chips were milled into sweet potato flour and the sweet potato flour were sieved to obtain fine flour and stored in plastic containers with lids in a refrigerator from where samples were drawn for Biscuits preparation (Figure 1).




Table 4.1: Proximate Composition of Wheat-Sweet Potato Flour Biscuits





This research work was carried out in order to test the proximate and sensory qualities of wheat-sweet potato composite biscuits. The use of potato in supplementing wheat flour in biscuitsproduction has significant benefits in countries where inadequate wheat is grown therefore, incorporation of sweet potato flour in biscuits production will reduce the quantity of wheat that will be imported,thereby reducing the cost of production of biscuits supplementing wheat with sweet-potato flour in biscuitsproduction will reduce over reliance on the use of wheat flour production and other baked products and will enhance the utilization of sweet potato in Nigeria


The results of this research work suggest that the possible utilization of composite flour produced from sweet potato and wheat. Further research work should be carried out to ensure its wild use.


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