Pineapple Vinegar to Enhance Shelf Life of Carrot and Mango in

Click here to load reader

download Pineapple Vinegar to Enhance Shelf Life of Carrot and Mango in

of 87

  • date post

    01-Jan-2017
  • Category

    Documents

  • view

    214
  • download

    0

Embed Size (px)

Transcript of Pineapple Vinegar to Enhance Shelf Life of Carrot and Mango in

Pineapple Vinegar to Enhance Shelf Life of Carrot and Mango in Tanzania

Aldegunda Sylvester Matunda

Thesis submitted to the faculty of the Virginia Polytechnic Institute and State University in partial fulfillment of the requirements for the degree of

Master of Science in Life Science In Food Science and Technology

Sean F. O'Keefe Co-Chair Kumar Mallikarjunan Co-Chair

Susan Duncan Amanda Stewart Richard Mongi

6/04/2015 Blacksburg, VA

Keywords: Pineapple, mango, carrot, vinegar, sensory evaluation, consumer

acceptability, Vitamin A, Vitamin C:

Pineapple Vinegar to Enhance Shelf Life of Carrot and Mango in Tanzania

Aldegunda Sylvester Matunda

ABSTRACT Fruits and vegetables are highly perishable, produced seasonally, and large

quantities (about 50-60% of production) are wasted during high season due to poor

handling and lack of cold storage in Tanzania. Processing excess pineapple into vinegar

which can be used for preservation of other fruits and vegetables may be a helpful

strategy for reducing losses. Vinegar was produced from pineapple juice supplemented

with sugar to produce different degrees of Brix (13, 20 and 30) and was fermented with

Saccharomyces cereviciae, Acetobacter pasteurianus, and Gluconobacter oxydans.

Levels of acetic acid were measured in the vinegar produced. High production (5.8%) of

acetic acid was observed with pineapple juice concentrated to 130 Brix with the

combination of Saccharomyces cerevisiae, A. pasteurianus and G. oxydans.

The pineapple vinegar produced was used for preservation of carrot and mango.

The pH of carrot pickle and mango chutney was monitored for three months. The pH of

preserved carrot and mango was below 4 and no significant changes in pH were observed

during three months storage at 29-320C. Chemical analysis of vitamin A and vitamin C

showed high losses of Vitamin A in carrot and increased vitamin A in mango, but losses

of about 74% and 85% of vitamin C were observed in carrot and mango after processing.

Consumer sensory testing of pineapple vinegar, carrot pickle and mango chutney

showed no significance different on overall consumer acceptability of products during

storage. Pineapple vinegar can be used to rescue mango and carrots that would otherwise

be lost, producing highly acceptable food products in Tanzania.

iii

Acknowledgement

I sincerely appreciate USAID for sponsoring my study, iAGRI stuff in Tanzania

for their assistance, and Sokoine University for allowing me to use their lab facilities.

Stewart Mwanyika, lab technician in the food science lab at Sokoine University,

supported me greatly during lab work in Tanzania.

My committee members, Dr. Richard Mongi, Dr Suzan Duncan, Dr. Amanda

Stewart, Dr. Kumar Malkarjunan, are thanked for their advice and contributions to my

study; it was great to have each of them on my committee.

My thanks to Ken and Kim for their assistance in lab work at Virginia Tech; it

was very helpful and grateful to work under your assistance.

Special appreciation to my advisor Dr. Sean OKeefe for being my advisor; I am

very grateful to work with him when I was in US and even when I was outside US he

continued to provide the same assistance and support.

My special gratitude goes out to my husband, my son and my family for their

encouragement and love during my study, especial when I was away from my country; it

was nice to have them on my side.

My friends and everyone who helped me during my study, it was nice to have all

of you on my side.

iv

Dedication

I dedicate this work to my beloved son, Carrington Victor, for his patience and

tolerance of my absence, which made it hard to concentrate on my studies. His love was

my strength in whatever I did. My husband, with his love and support during my studies,

made me feel strong in my work. My mother (Mary Matunda) for her prayers during my

studies, my sisters (Avelina Matunda and Marytreza) for their love and encouragement

during my studies, my mother (Agnes Muhabuki) for taking care of my son during my

studies, keeping my son healthy and safe was encouraging me and strengthened me

during my studies.

v

Abbreviations

FAO - Food Association Organization

MAFC - Ministry of Agriculture, Food Cooperatives.

Ho - Null hypothesis

Ha - Alternative hypothesis

pH- negative log of hydrogen ion concentration

WHO World Health Organization

ATCC American Type Culture Collection

USA United State of America

SUA Sokoine University of Agriculture

GAP Good Agricultural Practices

GMP Good Management Practices

GHP Good Hygiene Practices

TSS Total Soluble Solid

IRB Institutional Review Board

NIMR National Institute for Medical Research

THSD Tukeys Honest Significant Difference

AAB Acetic Acid Bacteria

s.d standard deviation

CV Commercial Vinegar

A.p - Acetobacter pasteurianus bacteria

O Gluconobacter oxydans bacteria

P13 Pineapple juice concentrated to 13 degree Brix

vi

P20 Pineapple juice concentrated to 20 degree Brix

P30 Pineapple juice concentrated to 30 degree Brix

vii

Table of ContentsAcknowledgement ............................................................. Error! Bookmark not defined.

Dedication .......................................................................................................................... iv

Abbreviations ...................................................................................................................... v

List of figures ..................................................................................................................... xi

List of tables ...................................................................................................................... xii

Chapter 1 ............................................................................................................................. 1

1.0 Introduction ................................................................................................................... 1

1.1 Background information ............................................................................................... 1

1.2 Problem statement ......................................................................................................... 2

1.3 Objective of the study ................................................................................................... 3

1.3.1. Specific objectives and hypotheses: .......................................................................... 3

Chapter 2 ............................................................................................................................. 5

2.0 Literature Review.......................................................................................................... 5

2.1. Introduction .................................................................................................................. 5

2.2 Fruits ............................................................................................................................. 6

2.2.1 Pineapple .................................................................................................................... 6

2.2.2 Mango ........................................................................................................................ 6

2.2.3 Carrot ......................................................................................................................... 6

2.3 Post-harvest losses of fruits and vegetables in Tanzania .............................................. 7

2.4 Vinegar .......................................................................................................................... 8

Chapter 3 ........................................................................................................................... 10

viii

3.0 Material and Methods ................................................................................................. 10

3.1. Study area................................................................................................................... 10

3.2 Raw materials. ............................................................................................................. 10

3.3 Vinegar Processing ..................................................................................................... 10

3.4 Preserving carrot and mango with vinegar ................................................................. 13

3.5 Chemical analysis ....................................................................................................... 17

3.5.1 Measurement of total soluble solids ........................................................................ 17

3.5.2 Measurement of pH .................................................................................................. 17

3.5.5 Consumer sensory evaluation of pineapple vinegar ................................................ 18

3.5.6 Statistical data analysis