Life Sciences Commons^™

The Use Of Membrane Filtration To Increase Native Whey Protein In Infant Formula, And Effects On Bioaccessibility And Bioactivity, Yihong Chen

Theses

Breastfeeding is recognised as the gold standard for feeding newborns and infants. However, infants who cannot be breast-fed or for whom breast milk is not available, can be fed with bovine infant milk formula (IMF) as a substitute. Researchers and producers of IMF strive to continually improve or “humanise” the composition and functionality of IMF. During production of IMF it must undergo several heat treatment steps, e.g. heat-sterilisation or spray-drying, in order to provide a safe product to the infant. These heat treatments denature the globular whey proteins in IMF. In contrast, breast milk is by its nature unheated, so …

Investigating Optimal Lipid:Protein Profiles For Infant Milk Formula, Valentina Ivanova

Theses

From the early twentieth century onward, much research has focused on improving infant milk formula (IMF). During the development of IMF, breast milk is commonly considered as the reference and IMF manufacturers are thriving to mimic the composition and/or to match the functionality of breast milk as closely as possible. A variety of bioactive ingredients, found in human breast milk, have been isolated and investigated for their potential functionality and utilised in the production of IMF. This study evaluated the current knowledge on compositional differences between human breast milk and IMF, and recent advances and developments in IMF production. Following …

Lactic Acid Bacteria Isolated From Fresh Vegetable Products: Potential Probiotic And Postbiotic Characteristics Including Immunomodulatory Effects, Fatima Khaled Alameri

Theses

The ability to perform effectively in the gastrointestinal system (GIT) is one of the most significant criteria for selecting the best probiotic bacteria. Thus, the present study aimed to investigate the potential probiotic characteristics of some selected lactic acid bacteria (LAB) isolated from vegetable products. Probiotic characteristics included tolerance to acid and bile, cholesterol removing ability, bile salt hydrolysis, resistance against lysozyme and antibiotics, production of exopolysaccharides (EPS), antimicrobial and hemolytic activities, and cell surface characteristics (auto-aggregation, co-aggregation, and hydrophobicity). Out of 46 isolates, 17 isolates that exhibited remarkable survivability under gastrointestinal conditions were selected for further analysis. Almost all …

A Study On Plant-Derived Small Proteins And Peptides With Antiyeast Activity And Preliminary Investigations In Food Materials, Giulia Mignone

Theses

The discovery of novel antimicrobial molecules would benefit considerably different biotechnological fields, including medicine, agriculture and the food industry, on which this thesis work focuses. Specifically, here are presented fundamental studies on plant-derived antimicrobial proteins for the reduction of food spoilage caused by yeast microorganisms. Small proteins and peptides from the plant innate immune system possess several characteristics which could make them ideal candidates for a novel and natural antispoilage agent. The first Chapter reviews proteins families associated with the plant innate immune system that exhibit antiyeast activity and low molecular weight (<30 kDa), focusing on their structure and antiyeast mode of action. Chapter 2 investigates two peptides, Pn-AMP1 and Pn-AMP2 belonging to the hevein-type peptides family; peptides were synthetically generated using their native amino acid sequence. Synthetic Pn-AMP1 showed fast action activity against common food spoilage yeasts, it resulted potentially safe for consumption, and it was successfully incorporated in UHT milk and Fanta Orange, where it contained the growth of Kluyveromyces lactis and Zygosaccharomyces bailii, respectively. A different family of antimicrobial plant proteins (2S albumins) was studied in Chapters 3, 4, 5 and 6. Chapter 3 describes the selective extraction of an antiyeast protein (labelled WMS1 in this thesis work) of ~14 kDa from white mustard (Brassica hirta) seeds. The protein was purified in a relatively high yield, using a simple protocol that included only one chromatographic method step. In Chapter 4, bioinformatics tools and wet-lab techniques are used to study the structure and classify the antiyeast protein. The WMS1 antiyeast protein was identified as an isoform of the Napin protein Allergen Sin a 1 belonging to the 2S albumins family, characterised by high structural stability which donates to the protein resistance heat treatment and proteolytic degradation. Chapter 5 describes the antimicrobial spectrum of WMS1 , its antiyeast mechanism of action and its validity as preservative agent. Although WMS1 resulted potentially safe for consumption and inhibited the growth of Z. bailii in several beverage systems, its biotechnological potential is limited by its allergic properties. In Chapter 6, the protein WMS1 was cloned in a pET28a-MBP vector and expressed in an E. coli BL21 system. Interestedly, recombinant WMS1 and native WMS1 showed similar activity against the yeast Z. bailii. Thesis abstract 2 Chapter 7 includes a protocol for the rational design of ultra-short antimicrobial peptides. Since ultra-short antimicrobial sequences can be found within the sequence of any larger protein, the protocol was applied using WMS1 primary sequence, and seven ultra-short SinA-AMPs were chemically generated. Among the various SinA-AMPs, the peptide labelled SinA-pepIII had in vitro activity against several common yeast spoilage strains via membrane permeabilisation and it could be employed as a food preservative as it was pH- and heat- stable, potentially safe in terms of human consumption and it prevented the growth of Z. bailii in cranberry juice. The results obtained in this work offer new perspectives in the research for novel and clean-label food preservatives to fight the food waste phenomenon.

Effect Of High-Pressure Processing On Quality And Shelf Life Of Green Fresh Juice Produced From A Blend Of Fruit And Vegetable, Ahlam Abdulla Al Hammadi

Theses

The technology of high hydrostatic pressure (HPP) in food processing started to take huge attention in food industries due to its ability to increase the shelf life of processed products by inactivating food-borne microorganisms and undesired enzymes that cause changes not acceptable to the consumers. Because of the treatments take place at low temperatures and because no chemical preservatives are added, advantageous and give more value to the product and match consumer demand for healthy products.

Aims: The aim of this thesis was to study the effect of HPP on certain quality parameters of green fruit juice compared to the …

Sensory Evaluation Of Camel Milk, Reem Amer Al Kaabi

Theses

Camel milk is one of the most important sources of nutrients for humans in numerous arid and semiarid environments. Consumer acceptability and sensory analysis are decisive for the commercialization of camel milk. It is essential to understand the sensory qualities of camel milk because of its unfamiliarity and its typical sensory profile, which is different from that of bovine milk. This study aimed to evaluate a trained panel qualitative description of sensory characteristics as well as consumer acceptability and attitude towards pasteurized non-flavoured, flavoured, and camel milk powders. In the consumer acceptability test, samples were evaluated based on acceptability with …

Evaluation Of Chili Pepper (Capsicum Annuum), Tiger Nuts (Cyperus Esculentus), And Turmeric (Curcuma Longa) As Sources Of Antioxidant Compounds For The Potential Of Antiaging-Like Activity, Chelsea Toyer

Theses

Aging is a natural process that living organisms go through as they become older. In humans and other animals, aging is accompanied by several morphological changes, including the formation of wrinkles. Wrinkles are also caused by various environmental factors such as excessive exposure to sun or pollution, and continuous sleep deprivation. These environmental factors cause oxidation of skin cells and the degradation of subcutaneous fatty acids, leading to the formation of wrinkles. Skin care and wrinkle treatment products are part of a multimillion-dollar industry. Plant-based products are an alternative method for treating wrinkles and premature aging. Several antioxidants naturally found …

Effect Of High-Pressure Processing On Quality And Shelf Life Of Green Fresh Juice Produced From A Blend Of Fruit And Vegetable, Ahlam Abdulla Al Hammadi

Theses

Background: The technology of high hydrostatic pressure (HPP) in food processing started to take a huge attention in food industries due to its ability to increase the shelf life of processed products by inactivating food-borne microorganisms and undesired enzymes that cause changes not acceptable by the consumers. Because of the treatments take place at low temperature and because no chemical preservatives are added, advantageous and gives more value to the product and matches consumer demand for healthy products.
Aims: The aim of this thesis was to study the effect of HPP on certain quality parameters of green fruit juice compared …

Characterization And Bioactive Properties Of Young And Mature Soybean And Their Protein Hydrolysates, Amna Khalifa Mohammed Alnuaimi

Theses

Soybeans are known for their high protein content that could be substituted for animal proteins. The potential bioactive properties of mature soybean (MS) proteins and their hydrolysates have been widely explored. The aim of this study was to investigate and compare various in-vitro bioactive properties (antioxidant, anti-diabetic, anti-obesity, and anti-inflammatory) of young soybean (YS) and MS flour and their protein hydrolysates when subjected to in-vitro simulated gastrointestinal digestion (SGID) and enzymatic hydrolysis, respectively. In the first phase, SGID of YS and MS flour was carried out to mimic the human digestion, while in the second phase, enzymatic hydrolysis of the …

Production And Characterization Of Natural Date Fruit Powder (Pheonix Dactylifera L.), Fayeza Hasan

Theses

The aim of this thesis was to study the possibilities for production and the characterization of powder from ripened date fruits (Phoenix dactylifera L.). Various techniques including tray drying, freeze-drying, vacuum drying, microwave drying, convection drying were tested for their ability to dry the dates sufficiently to produce a dated powder. Six varieties of dates namely Barhi and Khalas (soft varieties), Sagi and Sukari (semi-dry varieties), and Barakawi and Gundeila (dry varieties) were evaluated for their drying characteristics. The drying parameters and the physicochemical characteristics were compared and a storage study for the date powder was conducted. It …

Effectiveness Of Food Safety Training On Knowledge, Atitude, And Practices (Kap) Of Homebased Food Business (Hfb) In Al Ain, Uae, Mariam Mohammed Al Kaabi

Theses

This research aimed at evaluating the levels of knowledge, relevant attitudes, and food safety practices (KAP) of food handlers that have home food businesses (HFB) in Al Ain city, UAE. It examined the effectiveness of the Essential Food Safety Training Program (EFST) in providing food safety Knowledge, attitude, and practices. A quantitative research method was conducted using a sample of 68 participants who responded to the questionnaires. Three research questions were used to guide the study and explore the differences of the level of Knowledge, Attitudes, and Practice (KAP) before and after training program by using a paired-samples t-test. This …

Investigating The Antioxidant, Immunomodulatory And Anti-Obesogenic Propertiesof Novel Bsg-Derived Extracts And Their Potential As Ingredients In Functional Foods For Older Adults, Suzanne O Brien

Theses

Brewer’s Spent Grain (BSG) represents a substantial waste product of the brewing industry, with 39 million tonnes generated globally every year. To date the primary use of BSG is as animal feed but there is significant interest in identifying alternative uses for this agro-industry by-product. BSG is rich in protein and fibre and is known to contain health-promoting bioactive compounds, thus one application would be in the area of functional foods. People are living longer and as the older adult population continues to increase globally so too is the prevalence of age-related chronic conditions. Diet plays an essential role in …

Prevalence, Antibiotic-Resistance And Growth Profile Of Vibrio Spp., Isolated From Imported Shellfish In The Local Markets, Hind Obaid Mohammed Al Rumaithi

Theses

Seafood-related human illness caused by Vibrio species is a major problem. Seafood is prone to contamination by pathogenic Vibrio bacteria especially, Vibrio mimicus, Vibrio parahaemolyticus, and Vibrio vulnificus. The study on the prevalence of this microorganism in seafood of the United Arab Emirates is vital due to the cultural background of the Emiratis as a coastal heritage. A study was conducted to assess the prevalence of Vibrio spp. in imported shellfish from local markets and to identify the Vibrio spp. examine the antimicrobial resistance and profile growth conditions of the isolated Vibrio. In the present study, …

Evaluation Of Phytochemical Composition And Anti-Cancer Potential In Root Extracts Of Moringa Peregrina (Forssk.) Fiori, Salama Khamis Sultan Saeed Al Kaabi

Theses

Natural products provide many bioactive lead molecules for the discovery of new medicines. Naturally, derived phytochemicals have exhibited tremendous biological activities including anticancer activity. More than 60% of antitumor medicines are closely associated with natural products. In the present study, hexane, chloroform, acetone and, methanol extracts from roots of Moringa peregrina were screened for phytochemical analysis and anticancer activity. Phytochemical analysis was performed by Gas Chromatography and Mass spectrometry (GC-MS). The anticancer potential of the extracts was done on the human breast cancer cell line (MCF-7) and cell viability was measured using WST-1 Cell Proliferation Assay Kit. The cell line …

Prevalence, Antibiotic-Resistance And Growth Profile Of Vibrio Spp., Isolated From Imported Fish In The Local Markets, Tarfa Ali Mohamed Abdalla

Theses

Seafood and fish are important food components for a large section of the world population. Seafood is prone to bacterial contamination, many are pathogenic to human and marine animals, and three species, Vibrio mimicus, Vibrio parahaemolyticus, and Vibrio vulnificus, are responsible for most cases of seafood-related human illness caused by Vibrio species. The study on the prevalence of these microorganisms in seafood of the United Arab Emirates is vital due to the cultural background of the Emiratis as a coastal heritage. A study was conducted to assess the prevalence of Vibrio spp. in imported fishes from local …

Prevalence, Antibiotic-Resistance And Growth Profile Of Vibrio Spp., Isolated From Imported Fish In The Local Markets, Tarfa Ali Mohamed Abdalla

Theses

Seafood and fish are important food components for a large section of the world population. Seafood is prone to bacterial contamination, many are pathogenic to human and marine animals, and three species, Vibrio mimicus, Vibrio parahaemolyticus, and Vibrio vulnificus, are responsible for most cases of seafood-related human illness caused by Vibrio species. The study on the prevalence of these microorganisms in seafood of the United Arab Emirates is vital due to the cultural background of the Emiratis as a coastal heritage. A study was conducted to assess the prevalence of Vibrio spp. in imported fishes from local …

Hyperspectral Imaging Evaluation Of The Freshness Of Mushrooms (Agaricus Bisporus), Meera Hmoud Saeed Aldhaheri

Theses

Hyperspectral imaging (HSI) is a non-destructive analytical tool that can be used for sensing multiple attributes of foods. This thesis evaluates the application of HSI for measuring the freshness of the mushroom Agaricus bisporus (A. bisporus) in comparison with traditional seed methods. Three separate experiments were performed with 135 mushroom samples stored either in packed or unpacked conditions for 11 days. The overall results suggest that the HSI spectral region between 400 and 1000 nm is suitable for the inspection of mushroom freshness. Two distinguishing variables that aligned with physicochemical and microbiological analysis were recognized. Moisture loss was the main …

Fat Uptake Reduction In Deep-Fried Chicken Breast, Lovie G. Matthews

Theses

Obesity is the deposit of excessive adipose tissue on the body due to the overconsumption of nutritionally inadequate foods. The fat in the deep-fat fried chicken is derived from the oil absorption during frying. High consumption of deep-fat fried foods may lead to cardiovascular diseases and obesity. The main objectives of this experiment were to reduce the fat uptake in deep-fat fried chicken breast by developing an edible coating made of chicken breast protein isolates (CPI) as well as replace the corn starch in batter with sweet potato starch to further examine the quality attributes of the battering systems. In …

A Modified Rcm Medium For The Growth Of Lactobacillus Bulgaricus, Ayowole Caleb Oyeniran

Theses

In this study, we modified reinforced clostridial medium (RCM) to selectively enumerate and isolate Lactobacillus bulgaricus, a probiotic and an important starter culture in the dairy industry. The disparity in the reported carbohydrate fermentation pattern of L. bulgaricus was used to develop a growth medium not only selective for L. bulgaricus but significantly inhibitory to the growth of other lactic acid bacteria. A recently modified RCM (mRCM) was optimized for this study by the addition of 0.5% fructose, 0.5% dextrose, 1% maltose and 0.25% sodium pyruvate while replacing lactose as a carbohydrate source. The cell recovery and bacterial counts of …

Isolation, Identification And Characterisation Of Enterococcus Faecalis Isolates For The Generation Of Multifuctional Bioactive Peptides From Milk, Kenneth Patrick Graham

Theses

Enterococci are lactic acid bacteria (LAB) that have the paradoxical position of possessing biochemical properties of technological importance, but are also considered as opportunistic pathogens capable of causing infection in immunocompromised patients. However, they have a long history of safe use in foods and have been evaluated in several studies for their role as starter, adjunct, probiotic and protective cultures. They show higher proteolytic activities than other LAB and have demonstrated the ability to produce bioactive peptides during the fermentation of milk. The aim of this project was to identify proteolytic Enterococcus faecalis isolates capable of generating health-promoting bioactive peptides …

Study Of Rheological, Chemical, And Microbiological Properties Of Chami, A Traditional Emirati Soft Chees, Aysha Othman Abdullah Al Katheeri

Theses

In this work, ten Emirati Chami cheese samples were collected and analyzed to determine their chemical composition, texture, rheology, and microbiological properties. Chami cheeses showed large variations in moisture (60.9–84.1%), protein (7.5–14.6%), fat (0.5–7.8%), and ash (3.4–8.0%) contents as well as in pH (3.6–4.4), and water activity (0.977–0.999%). The variation in fat content of samples suggested that extra fat was added; this added fat was either butter or vegetable oil as indicated by the fatty acid composition. The different samples showed peaks of variable size for fat melting. The sodium content in the 10 cheese samples varied from 223–2410 mg/kg, …

Bill Owens: A Us Craft Beer Pioneer, 1982-2001, Patrick Walls

Theses

Bill Owens is a pioneer in the United States craft brewing industry through his efforts as an advocate, writer, publisher, brewer, and entrepreneur who created a lasting legacy by influencing generations of brewers and beer fans. Owens wrote the first book on homebrewing equipment (How to Build a Small Brewery: Draft Beer in Ten Days in 1982). He opened the third brewpub in the country (Buffalo Bill's Brewery in Hayward, California in 1983) where, in 1985, he introduced the first commercial pumpkin beer among other beer style firsts. Owens published numerous brewery-focused magazines that featured many illustrious beer writers. …

Nutritional Labelling Providing Education On Its Usage Could It Impact On Patient's Food Choice Selection For Those In The Obese Classification?, Celia Lane

Theses

A build-up of too much body fat can cause significant health risks and development of medical conditions and disabilities (National Institute Clinical Excellence (NICE), 2014). The causes of obesity involve the disproportionate intake of calories that are not utilised (World Health Organisation (WHO), 2016). The rising trend towards obesity threatens to bankrupt medical systems (Heifer and Shultz, 2014). There has been a heighten awareness from the general public in the last decade of the affiliation between health and nutrition (Irish Universities Nutrition Alliance (lUNA), 2011). In light of the ever increasing obesity trend, individuals still desire to take control of …

Safaa Ahmed Hamdan Alghasyah Aldhanhani, Safaa Ahmed Hamdan Alghasyah Aldhanhani

Theses

Sudan grass (Sorghum x drummondii) is commonly grown for the production of animal fodder in the UAE. Cyperus conglomeratus (locally termed 'Thenda') is a sedge native to the UAE, and one of the very few plants that colonize soils of shifting desert dunes. The native plant is grazed by camels, and may thus have a potential for animal feed production. While Sudan grass is a mycotrophic plant that normally lives in symbiosis with arbuscular mycorrhizal fungi for facilitation of nutrient uptake, C. conglomeratus is a non-host to these root symbionts. In the deseli sedges rhizosheaths comprising of dense …

Development And Validation Of Gas Chromatographic Methods For Free Fatty Acid Determination In Dairy Products, David Mannion

Theses

Quantification of free fatty acids (FFA) in dairy products by gas chromatography flame ion'^ation detection is an important requirement for qua'ity, research, nutritional, authenticity and legislative purposes. Common procedures are typically variants of either the fatty acid methyl esterification (FAME) or direct on-column injection methods developed more than two decades ago. This study involved the development of an alternative novel derivatization method using butylation, incorporating automation, reducing solvent usage that is applicable for a wide range of dairy products. The accuracy, precision, linearity, limits of detection and limits of quantification of all three methods were assessed for the quantification of …

Listeria Monocytogenes'. A Genomic Perspective On Its Pathogenesis, Persistence And Bacteriophages., Aidan Casey

Theses

The objective of this study was to investigate the genetic characteristics of Listeria monocytogenes that contribute to the threat it poses to the food processing industry. Transcriptomic analysis of a persistent L. monocytogenes isolate following exposure to an industrial detergent identified key upregulations in biological processes involved m peptidoglycan biosynthesis, chemotaxis and motility. Two bacteriophages against serotype 4b and 4e isolates of L. monocytogenes were isolated and sequenced. Comparative genomic and functional analysis identified the receptor binding proteins in each phage, whi]e transmission electron microscopy demonstrated a conserved baseplate architecture which also exists in other Gram­positive phages. Comparative genomics of …

Exploiting Bacteriophages And Associated Peptidoglycan Hydrolases With Potential For Biocontrol In Food Related Applications, Lorraine Endersen

Theses

The work presented in this thesis describes the isolation and characterisation of novel bacteriophages, and the subsequent exploitation of their bactericidal properties against two opportunistic food related pathogens, Mycobacterium avium subsp. paratuberculosis (MAP) and Cronobacter sakazakii.

MAP is a proven animal pathogen known to cause Johne’s disease in cattle but has been implicated as a causative agent of Crohn’s disease in humans. Despite the fact that this association has yet to be proven, significant focus has been directed towards evaluating the consequences of consuming milk contaminated with MAP. Accordingly, six mycobacteriophages were isolated and characterised in terms of temperature and …

Studies On The Initial Stage Of Lipid Oxidation In Bulk Oils., Elizabeth Budilarto.

Theses

During the oxidation of bulk oils, oxidation products (i.e. peroxide values, conjugated dienes and thiobarbituric acid reactive substances) are formed gradually and increased sharply at the end of the induction period. Tocophero1s were consumed, some water was formed, and micelles increased in size during the induction period of vegetable oils oxidized in bulk. The evidence that the evolution of micellar size was in parallel with the end of induction period corroborates the recognition that micelles are the active site of oxidation. The interaction of α-tocophero1 and three synergists: ascorby1 palmitate, phosphatidy1choline and L-lysine were studied in cod liver oil, to …

Investigation Of Factors Influencing Trichloromethane Levels In Milk And Its Control., Siobhan Ryan

Theses

Trichloromethane (TCM) is an undesirable chemical residue that can develop in milk. While TCM levels in milk are not within ranges of public health concern, it is important that minimal levels are maintained in order to promote the marketing of Irish dairy products abroad. Germany has enacted strict regulations on TCM concentrations in foodstuffs with a recommended level of0.002 mg/kg and re-analyse those milks, subsequent to cause identification and provision of advice on reducing TCM levels in milk. Milk samples were analysed using Gas chromatography (GC) with electron capture detection. The GC method was adapted and a standard curve was …

Evaluation Of Novel Low Molecular Weight Antimicrobial Compounds Produced By Lactic Acid Bacteria., Jiahui Leona Guo

Theses

Fungal food spoilage plays a pivotal role in the deterioration of food and feed systems and some fungi are also able to produce compounds toxic for humans and animals. The mycotoxins produced by fungi can cause serious health hazards and include toxins which are cancerogenic, immunotoxic, teratogenic, neurotoxic, nephrotoxic or hepatotoxic effects and Kashin-Beck disease. In addition to this, fungal spoilage/pathogens cause losses of marketable quality and hygiene of foodstuffs, resulting in major economic problem throughout the world. Nowadays, food spoilage can be prevented using physical and chemical methods, but no efficient strategy has been proposed so far to reduce …