Reduction of Bioburden by Optimizing Gamma Dose for Enhancing Export Value of Pakistani Peaches

Tesis de Máster , 2014 , 89 Páginas , Calificación: A

Química - Bioquímica

Peach is the most commonly eaten stone fruit which grows in the temperate regions of
the world. These are also among the most exported fruits in term of volume and value.
Peaches, being perishable and susceptible to microbial spoilage, have a short shelflife.

The goal of this study was to determine the effect of gamma irradiation on the
microbiological and organoleptic properties of peaches and secondly, to determine the
effects of irradiation on shelf-life of the fruit. The fruit (local variety, No.4), at proper
maturity stage was collected and irradiated with 0.25, 0.5, and 0.75kGy dose, stored
under refrigerated (4
o
C) conditions for a period of three weeks. Total viable count,
Gram negative Enterobacteriaceae count, Salmonella-Shigella count, yeast and mold
count, loss in weight and decay percentage was evaluated after 7, 14 and 21 days of
storage (4
o
C). Data obtained from microbiological and sensory evaluations of
irradiated peaches was compared with the observations obtained from unirradiated
(control) samples. Microbial evaluation of the fruits revealed the presence of
Salmonella sonnie on SS agar and non fermentor spp. on macConkey agar. Ten types
of yeasts were isolated on potato dextrose agar and analyzed microscopically. Studies
showed total bacterial, yeast and molds significantly decreased with increasing dose
level. The sensory evaluation of the fruits revealed that irradiation preserves the
texture and appearance of fruit. The gamma-irradiation dose of 0.75kGy proved to be
effective in reducing weight loss and significantly (p≤0.05) delaying the decaying of
the fruit by 7 days under refrigerated (4
o
C) conditions. Statistical studies were carried
out using Duncan’s multiple range test (DMRT) and means were separated by LSD at
5 %. It is hoped that this particular type of research will help in improving export
quality of peaches.

Inhaltsverzeichnis (Table of Contents)

• List of figures
• List of Tables
• Abbreviations
• Abstract
• Introduction
• Literature Review
• Materials and Methods
• Results
• Discussions
• References

Zielsetzung und Themenschwerpunkte (Objectives and Key Themes)

This research project aims to investigate the effectiveness of gamma irradiation in reducing the bioburden of Pakistani peaches, thereby enhancing their export value and extending their shelf life. The study focuses on optimizing the gamma dose to achieve a significant reduction in microbial contamination while minimizing any negative impact on the quality and safety of the fruit.

• Impact of gamma irradiation on microbial load in peaches
• Optimization of gamma dose for bioburden reduction
• Effect of gamma irradiation on peach quality and safety
• Evaluation of the effectiveness of gamma irradiation in extending shelf life
• Potential of gamma irradiation for enhancing the export value of Pakistani peaches

Zusammenfassung der Kapitel (Chapter Summaries)

• Introduction: This chapter provides a comprehensive overview of the global peach industry, highlighting the significance of Pakistan as a major peach producer. It discusses the challenges faced by the Pakistani peach industry, including post-harvest losses due to microbial spoilage and the need for effective preservation methods. The chapter also introduces gamma irradiation as a promising technology for reducing bioburden and extending shelf life.
• Literature Review: This chapter presents a detailed review of existing literature on the use of gamma irradiation for food preservation, focusing specifically on its application in fruit and vegetable industries. It explores the mechanisms of action of gamma irradiation, its effectiveness in reducing microbial contamination, and its impact on fruit quality and safety. The chapter also discusses the regulatory aspects of gamma irradiation and its acceptance in international markets.
• Materials and Methods: This chapter outlines the experimental design and methodology employed in the study. It describes the selection of peach varieties, the preparation of samples, the irradiation process, and the microbiological analysis techniques used to assess the effectiveness of gamma irradiation in reducing bioburden. The chapter also details the methods used to evaluate the impact of gamma irradiation on peach quality parameters, such as weight loss, decay, and sensory attributes.
• Results: This chapter presents the findings of the study, including the quantitative data on the reduction of microbial load in peaches after gamma irradiation. It analyzes the impact of different gamma doses on the total bacterial count, Gram-negative Enterobacteriaceae count, Salmonella-Shigella count, and yeast and mold count. The chapter also presents the results of the quality evaluation, including the percentage decay, weight loss, and sensory attributes of irradiated peaches compared to control samples.

Schlüsselwörter (Keywords)

The keywords and focus themes of the text include gamma irradiation, bioburden reduction, peach preservation, food safety, export value, microbial contamination, shelf life, quality evaluation, and Pakistani peach industry.

• Curso: Biotechnology
• Calificación: A
• Autores: Uzma Sarwar (Autor), Mehwish Iqtedar (Autor), Shagufta Naz (Autor)
• Año de publicación: 2014
• Páginas: 89
• No. de catálogo: V289112
• ISBN (Ebook): 9783656894148
• ISBN (Libro): 9783656894155
• Idioma: Inglés
• Etiqueta: reduction, bioburden, optimizing, gamma, dose, enhancing, export, value, pakistani, peaches