Food Science Commons^™

Production And Storage Stability Of High Concentrated Micellar Casein And Its Effect On The Functional Properties Of Process Cheese Products, Ahmed Hammam

Electronic Theses and Dissertations

Micellar casein is a high-protein ingredient that can be used in process cheese products (PCP) formulations. PCP is a dairy food prepared by blending dairy ingredients (such as natural cheese, protein concentrates, butter, non-fat dry milk NFDM, whey powder, and permeate) with nondairy ingredients (such as sodium chloride, water, emulsifying salts, color, and flavors) and then heating the mixture with a continuous agitation to produce a homogeneous product with an extended shelf-life. The first objective of this study was to produce a highly concentrated micellar casein (HC-MC) and evaluate its storage stability. Skim milk was pasteurized at 76°C for 16 …

Atmospheric Cold Plasma Interactions With Microbiological Risks In Fresh Food Processing, Apurva Patange

Doctoral

Atmospheric cold plasma (ACP) is a novel emerging non-thermal technology that has attracted attention as a decontamination tool in several industrial, food and healthcare sectors. This study investigated the anti-microbial efficacy of ACP against microbiological risks associated with fresh foods. Treatment was performed using in-package ‘dry’ ACP technology and plasma functionalised liquid to decontaminate microorganisms, exploring the responses to real and challenging microbiological risks pertinent to both fresh foods themselves as well as the effluents generated from food processing industry. A range of critical control process parameters were investigated with respect to key pathogenic and spoilage microorganisms commonly implicated in …

Interpreting And Reporting Principal Component Analysis In Food Science Analysis And Beyond, D. Cozzolino, A. Power, J. Chapman

Articles

Principal component analysis (PCA) is one of the most widely used data mining techniques in sciences and applied to a wide type of datasets (e.g. sensory, instrumental methods, chemical data). However, several questions and doubts on how to interpret and report the results are still asked every day from students and researchers. This brief communication is inspired in relation to those questions asked by colleagues and students. Please note that this article is a focus on the practical aspects, use and interpretation of the PCA to analyse multiple or varied data sets. In summary, the application of the PCA provides …

Compound-Specific Isotope Analysis Of Amino Acids In Biological Tissues: Applications In Forensic Entomology, Food Authentication And Soft-Biometrics In Humans, Mayara Patricia Viana De Matos

Graduate Theses, Dissertations, and Problem Reports (ETD)

In this work we demonstrate the power of compound-specific isotope analysis (CSIA) to analyze proteinaceous biological materials in three distinct forensic applications, including: 1) linking necrophagous blow flies in different life stages to their primary carrion diet; 2) identifying the harvesting area of oysters for food authentication purposes; and 3) the ability to predict biometric traits about humans from their hair.

In the first application, we measured the amino-acid-level fractionation that occurs at each major life stage of Calliphora vicina (Robineau-Desvoidy) (Diptera: Calliphoridae) blow flies. Adult blow flies oviposited on raw pork muscle, beef muscle, or chicken liver. Larvae, pupae …

Utilizing The Parts Of Common Food Products As Functional Ingredients Part 1: Separation And Concentration Of Ω-3 Pufa-Rich Phospholipids By Hydration Of Krill Oil Part 2: Functional Properties Of A Concentrated Egg Yolk Protein Powder Using A One-Step Organic Solvent Extraction Process, Casey Lynn Showman

Graduate Theses, Dissertations, and Problem Reports (ETD)

The food industry separates food products into different parts to better utilize the functional and nutritional benefits of each fraction. The overall focus of this thesis is on separating and utilizing fractions and co-products from food manufacturing as functional ingredients. Therefore, the objective of this research was to 1) evaluate the effectiveness of water degumming to separate omega-3 PUFA-rich phospholipids from other lipids found in krill oil and 2) determine how different organic solvents would affect physiochemical and functional properties of egg yolk protein recovered from spray-dried egg yolk using a novel one-step organic solvent extraction method.

The aim of …

Farm To Label: A Critique Of Consumer Activism In The Sustainable Food Movement, Olivia Whitener

Pomona Senior Theses

“Local,” “organic,” “natural,” and “Fairtrade” are just several of the many claims adorning the food products that line grocery store shelves. These promises of environmental sustainability and social responsibility are pillars of the “good food revolution” sweeping the nation as consumers demand alternatives to the products of the industrial food system. Green consumerism, the premise that consumer demand for environmentally sustainable goods will bring about ecologically beneficial outcomes, is at the heart of the sustainable food movement. This thesis takes a critical look at the operation of green consumerism in the food system. It explores the ideology and shortcomings of …

Nanostructured Materials For Food Applications: Spectroscopy, Microscopy And Physical Properties, Shubham Sharma, Swana Jaiswal, Brendan Duffy, Amit Jaiswal

Articles

Nanotechnology deals with the matter of atomic or molecular scale. Other factors that define the character of a nanoparticle are its physical and chemical properties, such as surface area, surface charge, hydrophobicity of the surface, the thermal stability of the nanoparticle, and its antimicrobial activity. A nanoparticle is usually characterized by using microscopic and spectroscopic techniques. Microscopic techniques are used to characterize the size, shape, and location of the nanoparticle by producing an image of the individual nanoparticle. Several techniques, such as scanning electron microscopy (SEM), transmission electron microscopy/high resolution transmission electron microscopy (TEM/HRTEM), atomic force microscopy (AFM) and scanning …

Thermostable Phytase In Feed And Fuel Industries, Ushasree Mrudula Vasudevan, Amit Jaiswal, Shyam Krishna, Ashok Pandey

Articles

Phytase with wide ranging biochemical properties has long been utilized in a multitude of industries, even so, thermostability plays a crucial factor in choosing the right phytase in a few of the sectors. Mesophilic phytases are not considered to be a viable option in the feed industry owing to its limited stability in the required feed processing temperature. In the recent past, inclusion of thermostable phytase in fuel ethanol production from starch based raw material has been demonstrated with economic benefits. Therefore, considerable emphasis has been placed on using complementary approaches such as mining of extremophilic microbial wealth, encapsulation and …

Efficacy Of Cold Plasma Functionalised Water For Improving Microbiological Safety Of Fresh Produce And Wash Water Recycling, Apurva Patange, Peng Lu, Daniela Boehm, Patrick J. Cullen, Paula Bourke

Articles

Atmospheric cold plasma (ACP) is an effective method for microbiological decontamination. This study evaluated an alternative water-based decontamination approach for inactivation of bacterial population from fresh produce and in the wash water generated from fresh produce washing. The study characterised ACP inactivation of attached Listeria innocua and Pseudomonas fluorescens inoculated on lettuce in comparison to chlorine treatment. P. fluorescens was sensitive to ACP treatment and was reduced below detection limit within 3 min of treatment. L. innocua population was reduced by ∼2.4 Log10 CFU/g after 5 min of treatment; showing similar inactivation efficacy to chlorine treatment. The microbial load in …

Improving Enzymatic Hydrolysis Of Brewer Spent Grain With Nonthermal Plasma, Rajeev Ravindran, Chaitanya Sarangapani, Swarna Jaiswal, Peng Lu, Patrick J. Cullen, Paula Bourke, Amit Jaiswal

Articles

In this study, a new pre-treatment method based on novel non-thermal plasma technology was developed to improve the enzymatic hydrolysis of brewer’s spent grain (BSG) and subsequent bioethanol production. A submerged dielectric barrier discharge plasma reactor system was applied for this purpose. Pre-treatments were performed by taking into account variables including; voltages (22 kV, 25 kV and 28 kV), solvent (acid, alkali and water) and time (5, 10, 15 min). The resulting treated biomass was subjected to enzymatic hydrolysis. A 2.14-fold increase in yield of the reducing sugar was achieved post hydrolysis when the biomass was treated in water for …

Exploring How Age Influences Sensory Perception, Thirst And Hunger During The Consumption Of Oral Nutritional Supplements Using The Check-All-That-Apply Methodology, Emma Regan, Graham O'Neill, Scott C. Hutchings, Dolores O'Riordan

Articles

The Check-all-that-apply (CATA) method has been widely used for the sensory characterisation of many different foods and beverages. However, this methodology has been rarely used with older adults. The aim of this study was to measure the effectiveness of the CATA methodology to investigate the differences in sensory perception of Oral Nutritional Supplements (ONS) between younger and community dwelling older adults over successive sips of a full volume of two ONS. The study also sought to measure the effects of ONS on thirst, hunger and fullness. 160 participants (eighty aged over 65 and eighty aged 18-35) evaluated two ONS over …

A Review Of Human Factors And Food Safety In Ireland, Ciara Walsh, Maria Chiara Leva

Articles

Increased product shelf-life and globalisation have led to longer and vastly more complicated food chains; potentially presenting greater opportunity for contamination and microbial growth to occur. Modern food safety management systems risk assess hazards (based on current scientific data) and strive to control these, often extensive and convoluted, food production/supply chains through appropriate good hygiene practices (GHP) and HACCP. Contamination of food as a result of human error can undermine even the most carefully prepared and executed HACCP system – culminating in foodborne infection, outbreaks, reputable damage, and erosion of consumer trust. This paper provides a review on the effect …

Growing South Dakota (Winter 2019), College Of Agriculture, Food And Environmental Sciences

Growing South Dakota (Publication of the College of Agriculture, Food and Environmental Sciences)

This is issue contains the South Dakota Agricultural Experiment Station 2018 Annual Report, and the SDSU Extension 2018 Annual Report.

[Page] 2 Setting Into role as Dean
[Page] 4 Raven Precision Ag Center Groundbreaking Ceremony
[Page] 10 Collaborating for Research-Based Solutions
[Page] 12 From the SDSU Extension Director
[Page] 14 Empowering South Dakotans Through Training and Certifications
[Page] 18 Mental Health and Opioid Education
[Page] 21 Science of Agriculture
[Page] 23 Community Gardens Bring Hope to Pine Ridge Indian Reservation
[Page] 26 Energize! Conference
[Page} 28 Disaster Preparedness Training
[Page] 30 Bush Foundation Change Network
[Page] 32 SDSU to Participate …

Assessing The Utility Of Multiplexed Liquid Chromatography-Mass Spectrometry For Gluten Detection In Australian Breakfast Food Products, Haili Li, Utpal Bose, Sally Stockwell, Crispin A. Howitt, Michelle Colgrave

Research outputs 2014 to 2021

Coeliac disease (CD) is an autoimmune disorder triggered by the ingestion of gluten that is associated with gastrointestinal issues, including diarrhea, abdominal pain, and malabsorption. Gluten is a general name for a class of cereal storage proteins of wheat, barley, and rye that are notably resistant to gastrointestinal digestion. After ingestion, immunogenic peptides are subsequently recognized by T cells in the gastrointestinal tract. The only treatment for CD is a life-long gluten-free diet. As such, it is critical to detect gluten in diverse food types, including those where one would not expect to find gluten. The utility of liquid chromatography-mass …

Characterization Of Polyphenols In Australian Sweet Lupin (Lupinus Angustifolius) Seed Coat By Hplc-Dad-Esi-Ms/Ms, Liezhou Zhong, Gangcheng Wu, Zhongxiang Fang, Mark L. Wahlqvist, Jonathan M. Hodgson, Michael W. Clarke, Edwin Junaldi, Stuart K. Johnson

Research outputs 2014 to 2021

Seeds of the legume lupin (Lupinus spp.) are becoming increasingly important as human food. The seed coat, at ~25% of the whole seed of Lupinus angustifolius (Australian sweet lupin, ASL), is the main by-product of lupin kernel flour production. The primary market for lupin seed coat is low value feed with very limited use in foods. In this study, seed coats of six ASL commercial varieties from two growing sites were sampled for identification and quantification of polyphenols using a high-performance liquid chromatography (HPLC) with diode array detector (DAD) and coupled with a triple quadrupole mass spectrometer which equipped with …

On The Use Of Vibrational Spectroscopy And Scanning Electron Microscopy To Study Phenolic Extractability Of Cooperage Byproducts In Wine, Berta Baca‑Bocanegra, Julio Nogales‑Bueno, Brian Gorey, Francisco José Heredia, Hugh Byrne, José Miguel Hernández‑Hierro

Articles

Wood is an important source of phenolic compounds, which can be transferred to wine during aging process, improving its properties, from an organoleptic point of view. Therefore, understanding and optimizing the extractability of phenolic compounds from wood are crucial in the oenological field. The structural composition of oak wood samples has been evaluated using Raman and attenuated total reflectance Fourier transform infrared (ATR–FTIR) spectroscopies, and their main spectral features have been linked to phenolic compound extractabilities, as measured by classic chemical analyses. To support the analysis, microscopic images of the samples were also recorded using scanning electron microscopy (SEM). The …

Evaluating Food Safety Knowledge And Practices Among Foodservice Staff In Al Madinah Hospitals, Saudi Arabia, Anushree Priyadarshini, Nada Ahmad Alqurashi, Amit Jaiswal

Articles

This study examines food safety knowledge and practices of food service staff in Al Madinah hospitals, Saudi Arabia. A total of 163 food service staff participated voluntarily from 10 hospitals across the city of Al Madinah. The participants completed a questionnaire composed of threeparts: Generalcharacteristics,foodsafetyknowledge,andfoodsafetypractices. Resultsshowed that respondents generally had good food safety knowledge with the highest pass rate of 77.9% for knowledge of cross contamination followed by 52.8% for knowledge of food poisoning, and 49.7% of knowledge of food storage. Food safety practices were also strongly observed in the hospitals with a pass rate of 92.6%. Food safety knowledge …

Investigation Of Mechanisms Involved In Germination Enhancement Of Wheat (Triticum Aestivum) By Cold Plasma: Effects On Seed Surface Chemistry And Characteristics, Agata Los, Dana Ziuzina, Daniela Boehm, Patrick J. Cullen, Paula Bourke

Articles

Recent reports indicate that atmospheric cold plasma (ACP) treatment of seeds can enhance their germination, however, the mechanisms of action are not yet entirely clear. In the present work, we report on the effects of plasma treatment on wheat seed germination and seedling growth. Additionally, changes in the surface chemistry and characteristics of the wheat seeds exposed to plasma were investigated. Treatments of 30–60 s significantly enhanced the germination rate and showed positive effects on seedling growth. ACP resulted in changes of seed surface and chemical characteristics including water uptake and contact angle values. Changes in seed pH and total …

Rapid Analysis Of Magnesium In Infant Formula Powder Using Laser-Induced Breakdown Spectroscopy, Maria Markiewicz-Keszycka, Ming Zhao, Xavier Cama-Moncunill, Toufic El Arnaout, Dana Becker, Colm O'Donnell, P. J. Cullen, Carl Sullivan, Maria Piedad Casado-Gavalda

Articles

Laser-induced breakdown spectroscopy (LIBS) was investigated to determine magnesium (Mg) content in infant formula powder. To predict Mg content in the range established by the Codex Alimentarius, a partial least squares regression (PLSR) model was developed using a calibration data set (n = 30) based on full cross-validation and validated using an independent validation data set (n = 21). The prediction model performance was evaluated using the regression coefficients of determination (Rcv2 = 0.94 and Rp2 = 0.85) with the root mean square errors on cross-validation and prediction (RMSECV = 60 mg kg−1 and RMSEP = 80 mg kg−1). The …

High Voltage Atmospheric Cold Air Plasma Control Of Bacterial Biofilms On Fresh Produce, Apurva Patange, D. Boehm, Dana Ziuzina, Patrick J. Cullen, Brendan Gilmore, Paula Bourke

Articles

Atmospheric cold plasma (ACP) offers great potential for decontamination of food borne pathogens. This study examined the antimicrobial efficacy of ACP against a range of pathogens of concern to fresh produce comparing planktonic cultures, monoculture biofilms (Escherichia coli, Salmonella enterica, Listeria monocytogenes, Pseudomonas fluorescens) and mixed culture biofilms (Listeria monocytogenes and Pseudomonas fluorescens). Biotic and abiotic surfaces commonly occurring in the fresh food industry were investigated. Microorganisms showed varying susceptibility to ACP treatment depending on target and process factors. Bacterial biofilm populations treated with high voltage (80 kV) ACP were reduced significantly (p <  0.05) in both mono- and mixed species biofilms after 60 s of treatment and yielded non-detectable levels after extending treatment time to 120 s. However, an extended time was required to reduce the challenge mixed culture biofilm of L. monocytogenes and P. fluorescens inoculated on lettuce, which was dependent on biofilm formation conditions and substrate. Contained treatment for 120 s reduced L. monocytogenes and P. fluorescens inoculated as mixed cultures on lettuce (p <  0.05) by 2.2 and 4.2 Log10 CFU/ml respectively. When biofilms were grown at 4 °C on lettuce, there was an increased resistance to ACP treatment by comparison with biofilm grown at temperature abuse conditions of 15 °C. Similarly, L. monocytogenes and P. fluorescens exposed to cold stress (4 °C) for 1 h demonstrated increased tolerance to ACP treatment compared to non-stressed cells. These finding demonstrates that bacterial form, mono versus mixed challenges as well as environmental stress conditions play an important role in ACP inactivation efficacy.

Effect Of Cold Plasma On The Techno-Functional Properties Of Animal Protein Food Ingredients, Juan M. Pérez-Andrés, Carlos Álvarez, Patrick J. Cullen, Brijesh K. Tiwari

Articles

Proteins, as food ingredients, are employed in the food industry, not only for their high nutritional value, but also because of their techno-functional properties. Modifications of their native structure due to the action of external factors such as pH, temperature or processing by emerging technologies, can lead to changes in their functionality; and consequently, their applicability. The present study investigates the effects of cold atmospheric air plasma on the techno-functional properties of two common food ingredients (haemoglobin and gelatine from pork), and a novel source of functional proteins extracted from a meat co-product (bovine lung protein). Significant effects were found …

Wholesomeness And Safety Aspects Of Irradiated Foods, Rajeev Ravindran, Amit Jaiswal

Articles

Food processing techniques are inevitable technological measures that aim to increase and sustain the quality of agricultural products. This is traditionally achieved by the application of heat or exposure to chemicals. Since the advent of X-rays, food scientists have been evaluating the prospect of employing ionising radiations for pest removal, sprouting inhibition and shelf-life extension of food products. Gamma radiation, electron beam and X-rays have emerged as the favoured methods of food irradiation in recent years. Several decades of research have endeavoured to determine the advantage and disadvantage of subjecting food materials to radiation. This has resulted in several international …

Evaluation Of Brewer's Spent Grain Hydrolysate As A Substrate For Production Of Thermostable Α-Amylase By Bacillus Stearothermophilus, Rajeev Ravindran, Gwilym A. Williams, Amit Jaiswal

Articles

In the present study, BSG was hydrolysed using cellulolytic enzymes and used as a growth medium supplement for cultivation of the thermophilic bacterium, Bacillus stearothermophilus in the production of α-amylase. A central composite design involving five parameters and four levels viz. starch, peptone, KCl, and MgSO4 along with BSG hydrolysate was used to derive the optimal media composition. The fermentation was conducted using shake flasks for 36 h at a temperature of 50 °C and pH 7.0 at 220 rpm. Optimization trials revealed that maximal amylase production (198.09 U/ml) occurred with a medium composition of starch (0.2% w/v), peptone (0.2% …

Plasma-Treated Air And Water—Assessment Of Synergistic Antimicrobial Effects For Sanitation Of Food Processing Surfaces And Environment, Uta Schnabel, Oliver Handorf, Kateryna Yarova, Björn Zessin, Susann Zechlin, Diana Sydow, Elke Zellmer, Jörg Stachowiak, Mathias Andrasch, Harald Below, Jörg Ehlbeck

Articles

The synergistic antimicrobial effects of plasma-processed air (PPA) and plasma-treated water (PTW), which are indirectly generated by a microwave-induced non-atmospheric pressure plasma, were investigated with the aid of proliferation assays. For this purpose, microorganisms (Listeriamonocytogenes, Escherichiacoli, Pectobacteriumcarotovorum, sporulatedBacillusatrophaeus) were cultivated as monocultures on specimens with polymeric surface structures. Both the distinct and synergistic antimicrobial potential of PPA and PTW were governed by the plasma-on time (5–50 s) and the treatment time of the specimens with PPA/PTW (1–5 min). In single PTW treatment of the bacteria, an elevation of the reduction factor with increasing treatment time could be observed (e.g., reduction …

Direct Analysis Of Calcium In Liquid Infant Formula Via Laser-Induced Breakdown Spectroscopy (Libs), Xavier Cama-Moncunill, Maria Markiewicz-Keszycka, Patrick J. Cullen, Carl Sullivan, Maria Piedad Casado-Gavalda

Articles

The present work illustrates the potential of laser-induced breakdown spectroscopy (LIBS) for the direct analysis of liquid food products. The aim of the experiment was to predict calcium content in ready-to-feed infant formula. The analysis was performed by a LIBS system coupled to a liquid sample chamber with a rotatory wheel that presents the liquid to the laser beam as a thin film. Multivariate analysis with partial least squares regression (PLSR) was performed to correlate LIBS spectral data to reference calcium contents. The obtained PLSR model exhibited a good fit and linearity, as indicated by the coefficients of determination for …

Laser-Induced Breakdown Spectroscopy For Food Authentication, Maria Markiewicz-Keszycka, Raquel Cama-Moncunill, Maria Piedad Casado-Gavalda, Carl Sullivan, P. J. Cullen

Articles

With the globalisation of food markets, food authentication has become a significant concern worldwide to ensure food safety and to avoid origin and quality fraud. A multi-elemental fingerprint is a powerful tool for detection of adulterants and geographical origin of foods. Laser-induced breakdown spectroscopy (LIBS) is a promising technique that can provide a mineral fingerprint of food products. LIBS allows a rapid, high-throughput, micro-destructive and multi-elemental analysis of a wide range of samples type. It has already been demonstrated by several authors that LIBS can be successfully used for food authentication. Although LIBS shows excellent potential for at-line or portable …

Effect Of Cold Plasma Treatment On The Antigenicity Of Peanut Allergen Ara H 1, Harshitha Venkataratnam, Chaitanya Sarangapani, Orla Cahill, Catherine Barry-Ryan

Articles

The objective of this study was to investigate the effects of cold atmospheric plasma on the antigenicity of protein Ara h 1. Dry, defatted peanut flour (DPF), whole peanut (WP) were subjected to cold atmospheric plasma at voltage of 80 kV for different treatment durations (0, 15, 30, 45 and 60 min). The allergen samples were analyzed using SDS-PAGE, immunoblot and competitive ELISA. Furthermore, the secondary structure was examined using circular dichroism. SDS-PAGE results revealed no change in the protein intensity bands corresponding to Ara h 1 for both DPF and WP. Competitive ELISA of samples showed a reduction in …

Microencapsulation Of Probiotics Using Goat Milk And Konjac Glucomannan Hydrolysate Via Spray Drying, Sudhinee Harindhanavudhi

Chulalongkorn University Theses and Dissertations (Chula ETD)

Probiotics are beneficial for health when consuming in a sufficient amount. However, probiotics are not tolerant to high temperatures in food processing. Microencapsulation is one technique that using to entrap probiotic cells for applying in food products. Therefore, this research is aimed to study the application of konjac glucomannan hydrolysate (KGMH) in the combination of goat milk to encapsulate Lb. casei-01 by using microencapsulation techniques via spray drying. There were three main parts of this research. Firstly, KGMH from 15-25% (w/w) KGM were determined for prebiotic activity score (PAS) in in vitro. Besides, the positive effect of KGMH in goat …

Replacement Of Milk Fat With Other Fats In Processed Cheese Analogues, Pachara Pomsang

Chulalongkorn University Theses and Dissertations (Chula ETD)

This research is aimed to develop healthy processed cheese for Thai consumers by studying consumer needs, the physicochemical and sensory properties of the developed processed cheese. Thai consumers who concerned about their health in Bangkok (n=422) participated in a survey and 72.7% of the consumers had positive intention to the healthy cheesed product in sliced type. Eighty percent of the consumers expected their cheese product to be fortified with healthy ingredients such as antioxidants and omega fatty acids. Four processed cheese prototypes with different milk fat replacements (rice bran oil (RBO), soybean oil (SBO), palm oil (PO), and fish oil …

สมบัติเชิงหน้าที่ของยีนที่เกี่ยวข้องกับการเกิดเมลาโนซิสในกุ้งขาวแปซิฟิก Litopenaeus Vannamei, จันทร์วรางค์ เรืองปัถย์

Chulalongkorn University Theses and Dissertations (Chula ETD)

ฟีนอลออกซิเดส เป็นเอนไซม์ที่มีหน้าที่สำคัญในกระบวนการเมลาไนเซชัน ซึ่งเป็นส่วนหนึ่งของระบบ ภูมิคุ้มกันแต่กำเนิดในสิ่งมีชีวิตกลุ่มครัสเตเชียน ฟีนอลออกซิเดสจัดอยู่ในกลุ่มโปรตีนที่จับจำเพาะกับทองแดง สามารถเร่งปฏิกิริยาการเปลี่ยนสารประกอบฟีนอลให้เป็นควิโนน ซึ่งสามารถเกิดพอลิเมอไรเซชันต่อไปและกลายเป็นเมลานินซึ่งจุดดำเหล่านี้ก่อให้เกิดความเสียหายทางเศรษฐกิจต่ออุตสาหกรรมอาหารทะเลได้ ส่วนฮีโมไซ ยานินเป็นโปรตีนในกลุ่มที่จับจำเพาะกับทองแดงเช่นเดียวกับฟีนอลออกซิเดส มีหน้าที่ลำเลียงออกซิเจนในเลือด ของครัสเตเชียน และมีรายงานว่าหน่วยย่อยของฮีโมไซยานินมีกิจกรรมของเอนไซม์ฟีนอลออกซิเดสด้วยเช่นกัน แต่ยังไม่มีการระบุแน่ชัดว่าหน่วยย่อยใดของฮีโมไซยานินที่มีความสามารถดังกล่าว งานวิจัยนี้จึงสนใจศึกษา ลักษณะสมบัติและหน้าที่ของหน่วยย่อยฮีโมไซยานินชนิดใหม่ในกุ้ง Litopenaeus vannamei คือ LvHcB จาก การศึกษาด้านชีวสารสนเทศ พบว่า open reading frame ของยีน LvHcB ประกอบด้วยนิวคลีโอไทด์ 2004 คู่เบสถอดรหัสเป็นเพปไทด์ที่มีกรดอมิโน 650 ตัว โดยกรดอะมิโน 17 ตัว เป็นเพปไทด์ส่งสัญญาณ ลำดับกรดอะมิ โน ขอ ง LvHcB มีความ คล้าย กับ LvHcL แล ะ LvHcS เท่ากับ 69% แล ะ คล้าย LvproPO1 เท่ากับ 44% LvproPO2 เท่ากับ 45% และ LvproPO3 เท่ากับ 41% นอกจากนี้ LvHcB ยังมีลักษณะของโปรตีนใน กลุ่มโปรตีนที่จับจำเพาะกับทองแดงเช่นกัน จากการศึกษาหน้าที่ของยีน LvHcB ในกุ้งขาวด้วยเทคนิคอาร์เอ็นเอ อินเตอร์เฟียเรนซ์ พบว่าการลดการแสดงออกของยีน LvHcB ในกุ้งขาวด้วยการฉีด อาร์เอ็นเอสายคู่ที่จำเพาะต่อ ยีน LvHcB เข้าสู่กุ้ง ทำให้ปริมาณทรานสคริปต์ของยีน LvHcB ลดลงโดยไม่ลดปริมาณทรานสคริปต์ของยีนอื่นที่ เกี่ยวข้องกับเมลาโนซิส และยังพบว่ากุ้งที่มีการแสดงออกของยีน LvHcB ลดลงมีกิจกรรมของเอนไซม์ฟีนอลออกซิเดสน้อยกว่ากุ้งกลุ่มควบคุมที่ฉีดด้วยอาร์เอ็นเอสายคู่ของยีน GFP เมื่อตรวจสอบการเกิดเมลาโนซิสโดยการวัดสี ด้วยระบบ CIE L* a* b* พบว่า ΔE value ของกุ้งที่ถูกลดการแสดงออกของยีนด้วย LvHcB dsRNA มีค่าสูงกว่า กุ้งในกลุ่ม …