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Massey Research Online is an open access digital archive of the research and scholarship of Massey University and is jointly managed by the University Library and Information Technology Services.
Massey Research Online contains research theses and research outputs including published work by Massey University students and academic staff as well as peer-reviewed material not published elsewhere. In the case of previously published research outputs all requirements of copyright owners are observed.
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Soil nitrogen dynamics affected by coffee (coffea arabica) canopy and fertilizer management in coffee-based agroforestry
(Springer Nature BV in cooperation with ICRAF, 2024-08) Kurniawan S; Nugroho RMYAP; Ustiatik R; Nita I; Nugroho GA; Prayogo C; Anderson CWN
Nutrient management in coffee-based agroforestry systems plays a critical role in soil nitrogen (N) cycling, but has not been well documented. The objective of this study was to evaluate the effect of coffee canopy management and fertilization on soil N dynamics. This study used a randomized complete block design (2 × 3 × 2) with four replications. There were three factors: 1) coffee canopy management (T1: Pruned, T2: Unpruned), 2) fertilizer type (O: Organic, I: Inorganic; M: 50% Organic + 50% Inorganic), and 3) fertilizer dose (D1: low, D2: medium, D3: high). Soil N dynamic indicators (i.e., total N, ammonium (NH4+), nitrate (NO3−), net N-NH4+, net N-NO3−, soil microbial biomass N) were measured at two soil sampling depths (0–20 cm and 20–40 cm). Results showed that pruning increased soil total N and microbial biomass N (MBN) by 10–56% relative to unpruned coffee trees. In contrast, the unpruned coffee canopy had 15–345% higher NH4+, NO3−, net N-NH4+, net N-NO3−, and microbial biomass N concentration than pruned coffee. Mixed fertilizer application increased NO3− and net N-NH4+ accumulation by 5–15% relative to inorganic and organic fertilizers. In addition, medium to high dose fertilization led to a 19–86% higher net N-NO3− concentration and microbial biomass N as compared to low dose fertilization. The treatment of no pruning and mixed fertilizer at low to medium doses was the optimal management strategy to maintain soil available N, while pruning combined with organic fertilizer has the potential to improve soil total N and MBN.
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AI-Based Controls for Thermal Comfort in Adaptable Buildings: A Review
(MDPI AG, 2024-11-04) Ahsan M; Shahzad W; Arif K
Due to global weather changes and pandemics, people are more likely to spend most of their time in indoor environments. In this regard, indoor environment quality is a very important aspect of occupant well-being, which is often ignored in modern building designs. Based on our research, thermal comfort is one of the essential items in building environments that can improve the mental stability and productivity of the occupants if the building’s indoor environment is created in a way that meets the occupants’ comfort requirements. Buildings nowadays operate on adaptive or stationary models to attain thermal comfort, which is based on Fanger’s model of the Predicted Mean Vote (PMV). Based on the literature review, limited work has been carried out to enhance the quality of the inside environment, and most research work has been devoted to building energy management. Moreover, there have been no definite solutions so far that have the capability to detect the thermal comfort requirements of multiple occupants in real time. Modern buildings tend to operate on predefined set point parameters to control the indoor environment based on the measured room temperature, which can be different from the thermal comfort requirements of the occupants. This paper discusses the limitations and assumptions that are associated with the existing thermal comfort solutions and emphasises the importance of having a real-time solution to address the thermal requirements of occupants.
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Investigation of the microbiomes of sow skin, milk and piglet hind gut : a thesis presented in partial fulfilment of the requirements for the degree of Master of Science in Animal Science at Massey University, Manawatū, New Zealand
(Massey University, 2024) Jones, Sophia
There is a lack of information on the microbiome of sow skin, sow milk and piglet faeces from New Zealand production systems. Therefore, we have a current lack of data on the bacterial populations present and the potential pathways of transmission to colonise the gut of neonatal pigs. Knowledge of these aspects would allow the identification of common probiotics, pathogens and commensal bacteria in pigs and provide information to help identify the pathways of colonisation for bacteria within the gastrointestinal tract of neonatal pigs. Samples were collected from 21 sows (N = 17 milk samples and N = 20 udder skin swabs) and 63 piglets (N = 63 piglet faecal samples) within 72 hours of parturition, on a commercial farrow-to-finish indoor pig farm. The DNA extracted from these samples underwent metabarcoding analysis using the greengenes 16S database and Kraken2 pipeline. The number of reads varied by different samples, even from within the same pen. For example, the milk sample of sow 676 only had 25,000 reads whilst the piglets suckling from this sow had between 125,000 – 160,000 reads. Piglet samples were dominated by populations of Firmicutes and Bacteroidetes bacteria, whilst the sow udder skin and milk samples were dominated by populations of Firmicutes and Proteobacteria bacteria. Milk samples displayed a greater presence of lesser common phyla compared to sow skin or piglet faeces, but these phyla are present at relatively low levels of reads, such as Cyanonbacteria, Chloroflexi and Acidobacteria. There were no reads for Escherichia coli bacteria present in any samples taken for this study which is an unusual but incredibly positive finding. Clostridium, a similar pathogenic bacteria in neonates, was found abundant in piglet faecal samples so we cannot be sure if E. coli did not exist on-farm at all due to upkept disinfection protocols or if the piglets had not yet picked it up. Probiotic bacteria were identified across the piglet faecal samples, namely Pediococcus and Lactococcus, including species of the phyla which are known to increase production and performance, as well as providing a protective function against E. coli bacteria. As probiotic bacteria are typically given as feed additives pre-weaning due to benefits aiding in gut microbiota development, these piglets seem to already have a good basis of these bacteria. The research was successful in what was set out to be completed, despite any limitations that were discovered, and resulted in future recommendations to continue characterising important microbiomes in the New Zealand pork industry, as well as their interactions and pathways of transmission to neonatal piglets.
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Development and characterisation of plant-based (faba bean) yoghurt : a thesis submitted in partial fulfilment of the requirements for the degree of Master of Food Technology, Massey University, Palmerston North, New Zealand
(Massey University, 2024) Rankothge, Rohitha Somarathne
Increasing awareness of health, environmental, and ethical issues has recently increased the demand for plant-based alternatives to traditional dairy products. Plant-based milk might be a suitable choice for people looking for a healthier option because it often contains less fat, particularly saturated fat, and allergens. In recent years, the faba bean has gradually become popular as a plant protein due to its nutritional and health benefits to consumers. This master's thesis investigates the possibility of producing yoghurt using faba bean milk analogue (FBM), faba bean protein isolates (FPI) and faba bean-dairy hybrid as alternatives to traditional dairy yoghurt. Also, the effects of varying ratios of dairy and faba bean proteins on the texture, rheology, microstructure, nutritional makeup, protein digestibility, and sensory characteristics of yoghurt were investigated. This study aimed to optimize the formulation of faba bean yoghurt to develop a sustainable and nutrient-rich plant-based alternative to dairy yoghurt through a series of analytical procedures. The study's objectives include examining the interactions between faba bean milk analogue, faba bean protein isolates, and dairy milk (DM) in yoghurt production using five different formulations. These formulations include 50% dairy + 50% faba bean milk analogue (SM#2), 50% dairy + 50% faba bean protein isolates, 50% faba bean milk analogue + 50% faba bean protein isolates (SM#3), 100% faba bean milk analogue (SM#4), 50% faba bean milk analogue + 50% faba bean protein isolates (SM#5) and 100% faba bean protein isolates (SM#6). Further, assessing how these interactions affect the final product's texture, rheology, microstructure, and digestibility. The nutritional composition of various faba bean yoghurt formulations was analyzed, focusing on protein, fat, total solids, fibre, and starch content, and compared with traditional dairy yoghurt. The sensory survey was done using an internal untrained panel to evaluate the consumer preferences for different formulations based on attributes such as taste, aroma, texture, colour, and overall acceptability. Additionally, it investigated the influence of varying ratios of FBM, FPI and DM on the rate and extent of protein digestion using a static digestion (INFOGEST) model. Results indicated that yoghurts made with FPI exhibited higher storage (G’) and loss modulus (G”) values, indicating a stronger gel structure compared to those made with DM alone (reference). The product made with DM and FPI (SM#3) showed the lowest G’ and G”. Similar behaviour was observed for apparent viscosity as well. The product made with DM and FBM (SM#2), showed comparatively similar rheological properties. All yoghurt samples' loss tangent (tan δ) values were consistently less than one, indicating a mostly solid character. Texture profile analysis results of the samples showed a significant difference in textural properties like hardness, cohesiveness, springiness, gumminess, and adhesiveness between samples (p<0.05). SM#2 and SM#5 showed the least deviation from the reference (100% dairy yoghurt). Faba bean yoghurt also demonstrated better water-holding capacity and lower syneresis, particularly in formulations with higher FPI (50% and 100%) content (SM#5 & SM#6). Sensory evaluations showed that consumers preferred the formulations that closely matched the texture and flavour of traditional dairy yoghurt. The hybrid formulations of DM and FBM (SM#2) showed the least deviation from the reference (100% DM). In-vitro gastrointestinal digestion was conducted following the INFOGEST method to assess the protein digestibility of the yoghurt samples. Protein hydrolysis expressed as free amino N of all yoghurt samples by pepsin during the gastric phase (0 to 120 min) was relatively lower than in the small intestinal phase. However, all samples including 100% dairy reference showed a significant increase (p<0.05) in the release of free amino N upon the addition of pancreatin and bile salt during the simulated small intestine phase (130-240 min) compared to the gastric phase. The free amino N release (%) was significantly lower (p<0.05) in 100% plant-based yoghurts (SM#4, SM#5 & SM#6) compared to dairy and plant-based hybrid samples (SM#2 & SM#3). In conclusion, the findings suggested that faba bean yoghurt, particularly when blended with DM, can potentially meet consumer preferences and textural properties while providing a nutritious and sustainable alternative to dairy yoghurt. In addition, there is a high potential of producing 100% vegan yoghurt from faba bean proteins, but further studies on improving textural and sensory properties are needed. The study contributes to exploring the options available in the plant-based food market, addressing both environmental and nutritional needs.
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How Reproducible are Surface Areas Calculated from the BET Equation?
(Wiley-VCH GmbH, 2022-05-23) Osterrieth JWM; Rampersad J; Madden D; Rampal N; Skoric L; Connolly B; Allendorf MD; Stavila V; Snider JL; Ameloot R; Marreiros J; Ania C; Azevedo D; Vilarrasa-Garcia E; Santos BF; Bu X-H; Chang Z; Bunzen H; Champness NR; Griffin SL; Chen B; Lin R-B; Coasne B; Cohen S; Moreton JC; Colón YJ; Chen L; Clowes R; Coudert F-X; Cui Y; Hou B; D'Alessandro DM; Doheny PW; Dincă M; Sun C; Doonan C; Huxley MT; Evans JD; Falcaro P; Ricco R; Farha O; Idrees KB; Islamoglu T; Feng P; Yang H; Forgan RS; Bara D; Furukawa S; Sanchez E; Gascon J; Telalović S; Ghosh SK; Mukherjee S; Hill MR; Sadiq MM; Horcajada P; Salcedo-Abraira P; Kaneko K; Kukobat R; Kenvin J; Keskin S; Kitagawa S; Otake K-I; Lively RP; DeWitt SJA; Llewellyn P; Lotsch BV; Emmerling ST; Pütz AM; Martí-Gastaldo C; Padial NM; García-Martínez J; Linares N; Maspoch D; Suárez Del Pino JA; Moghadam P; Oktavian R; Morris RE; Wheatley PS; Navarro J; Petit C; Danaci D; Rosseinsky MJ; Katsoulidis AP; Schröder M; Han X; Yang S; Serre C; Mouchaham G; Sholl DS; Thyagarajan R; Siderius D; Snurr RQ; Goncalves RB; Telfer S; Lee SJ; Ting VP; Rowlandson JL; Uemura T; Iiyuka T; van der Veen MA; Rega D; Van Speybroeck V; Rogge SMJ; Lamaire A; Walton KS; Bingel LW; Wuttke S; Andreo J; Yaghi O; Zhang B; Yavuz CT; Nguyen TS; Zamora F; Montoro C; Zhou H; Kirchon A; Fairen-Jimenez D
Porosity and surface area analysis play a prominent role in modern materials science. At the heart of this sits the Brunauer-Emmett-Teller (BET) theory, which has been a remarkably successful contribution to the field of materials science. The BET method was developed in the 1930s for open surfaces but is now the most widely used metric for the estimation of surface areas of micro- and mesoporous materials. Despite its widespread use, the calculation of BET surface areas causes a spread in reported areas, resulting in reproducibility problems in both academia and industry. To prove this, for this analysis, 18 already-measured raw adsorption isotherms were provided to sixty-one labs, who were asked to calculate the corresponding BET areas. This round-robin exercise resulted in a wide range of values. Here, the reproducibility of BET area determination from identical isotherms is demonstrated to be a largely ignored issue, raising critical concerns over the reliability of reported BET areas. To solve this major issue, a new computational approach to accurately and systematically determine the BET area of nanoporous materials is developed. The software, called "BET surface identification" (BETSI), expands on the well-known Rouquerol criteria and makes an unambiguous BET area assignment possible.