Volume 10 • Issue 1 • 1000772
J Food Process Technol, an open access journal
ISSN: 2157-7110
Open Access Research Article
Journal of Food
Processing & Technology
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ISSN: 2157-7110
Ajifolokun et al., J Food Process Technol 2019, 10:1
DOI: 10.4172/2157-7110.1000772
*Corresponding author: Oluyinka Mary Ajifolokun, Department of Biochemistry and
Microbiology, University of Zululand, South Africa, E-mail: maryoluyinka2@gmail.com
Received October 23, 2018; Accepted December 06, 2018; Published December
11, 2018
Citation: Ajifolokun OM, Basson AK, Osunsanmi FO, Zharare GE (2018) Effects of
Drying Methods on Quality Attributes of Shrimps. J Food Process Technol 10: 772.
doi: 10.4172/2157-7110.1000772
Copyright: © 2018 Ajifolokun OM, et al. This is an open-access article distributed
under the terms of the Creative Commons Attribution License, which permits
unrestricted use, distribution, and reproduction in any medium, provided the original
author and source are credited.
Abstract
Shrimps are fresh and saltwater animal on aquatic habitat. They are known today as one of the fastest growing food
commodities in international trade, maybe as a result of their perceived health benefts, culinary attributes and importantly,
being a source of protein. The effects of two major drying methods; sun-drying and oven-drying at 50
°
C, 60
°
C or 70
°
C were
investigated on the nutritional, microbiological and sensory properties of shrimp powder. From the result of the study, it was
observed that the sun-dried shrimp powder had higher moisture content than the oven-dried shrimp powder. There were
slight variations in the proximate compositions of the shrimp powder. The total yeast count was higher in the sun-dried shrimp
powder (38 × 10
-5
cfu/g) and the lowest yeast count was observed in oven-dried shrimp powder at 70
°
C (19 × 10
-5
cfu/g).
Also, the oven-dried shrimp powder at 70
°
C had the lowest total viable count (TVC) of 12 × 10
-5
cfu/g while higher TVC was
observed in the sun-dried shrimp powder (36 × 10
-5
cfu/g). Neither mold nor coliform growth was observed on both sun-dried
and oven-dried shrimp powder. The result of the sensory evaluation revealed the signifcant effects of drying methods on the
sensory parameters of shrimps. There were signifcant differences in consumer preferences for aroma, appearance, color, taste
and overall acceptability. The oven-dried shrimp powder at 70
°
C was preferred in all parameters evaluated than the sun-dried
powder.
Effects of Drying Methods on Quality Attributes of Shrimps
Ajifolokun OM
1*
, Basson AK
1
, Osunsanmi FO
2
and Zharare GE
2
1
Department of Biochemistry and Microbiology, University of Zululand, South Africa
2
Department of Agricultural Science, University of Zululand, South Africa
Keywords: Shrimps; Saltwater; Food; Sun-dried
Practical Applications
Drying of a food material causes reduction of moisture content
from its water activity to a level which impacts some technological
advantages such as; prolonged shelf life, ease of transportation and
handling, impartment of desirable characteristics such as odor, color,
favor, and taste. Various drying methods are used to preserve shrimp,
which is aimed at preventing deterioration and spoilage before
consumption. However, some of these drying methods have negative
efects on the quality attributes of shrimps, which could reduce its
nutritional composition, consumer acceptability and caused a human
hazard. Terefore, this study investigated the best method for frying
shrimp that will not afect the nutritional, microbiological and sensory
characteristics of shrimps.
Introduction
Shrimps belong to the kingdom of Animatia, (phylum): Arthropoda,
(class): Crustacean, (order); Decapoda, (general): Penacus, species:
Penaeus kerathunes (zebra shrimp), Penacin notails (pink shrimps),
Oarapenaeosspsis atlantic (brown shrimp), Aristeus variden,
Plesiopenaeus edwardslanus and Parapenaues longwstir [1,2]. Shrimps
are characterized by the semi-transparent body which is laterally
compressed. Tey have two pairs of pre-oval appendages; which are
anti-uniform but sensory in functions, also a rostrum on which there
are teeth both on the ventral and dorsal surfaces [2].
Seafood, which includes shrimps, are dietary staple foods in many
countries and there is currently an increase in demand for seafood’s as
they are a very good source of polyunsaturated fatty acids called omega
and fatty acids [3]. Shrimps with their natural perceived health ftness
and culinary attributes are increasingly the protein choice of people
globally. Tey contain about 18%-20% protein, 75%-80% water, low fat
(4.5%), amino acids and minerals such as selenium, copper, zinc, and
calcium in right proportion [3,4]. Shrimps also contain polyunsaturated
fatty acids necessary to improve human health and are also rich in
astaxanthin and vitamin B
12
with antioxidant properties [2].
Te agents of spoilage in shrimps are bacteria and autolytic enzymes,
which operate under constraining optimum conditions. Bacteria
require water and are sensitive to heat, salt concentrations, and pH
while enzymes activities are sensitive to temperature changes but can
be inactivated by chemical irradiation [5]. Shrimps deteriorate rapidly
when captured because of their high moisture and protein content
unless they are preserved by cold storage condition [6].
Drying has been used to preserve food all over the world since
prehistoric times when people learned that sun-dried foods remain
wholesome for a longer time [7]. Drying of foods including shrimps
reduces the moisture content of foods to a safe level, which impacts
some technological advantages, such as increased shelf life, ease of
handling and transportation, impartment of desirable characteristics
such as odor, favor, color, and taste [8]. As water is essential for the
activities of all lung organisms, its removal will also slow down and stop
microbial or autolytic activities. Tis is because microorganisms need
water for growth and food enzymes cannot thrive without a watery
environment, therefore drying can be efectively used as a method of
preserving shrimps. Completely dried-shrimp or powdered-shrimps
have been widely accepted, as they can be used as spices in soups or
foods for favor and protein source [9].
Diferent drying methods have been used to process and preserve
shrimps such as; freeze-drying [10], super-heated air drying [11], heat
pump drying [12], solar drying [7], jet- emitted bed drying and hot air
drying [13]. Solar drier and hot air have been the most common and
cheapest processing methods of preserving shrimps because they require
less sophisticated eforts and inputs [14]. However, drying usually afect