Department of Wine, Food and Molecular Biosciences

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https://hdl.handle.net/10182/38

The Department of Wine, Food and Molecular Biosciences covers course areas including animal and plant science, biochemistry, food science, horticulture, microbiology, sensory science, viticulture and wine science.

Now showing 1 - 5 of 805

The Scoop on SCOBY (Symbiotic Culture of Bacteria and Yeast): Exploring consumer behaviours towards a novel ice cream
(Multidisciplinary Digital Publishing Institute (MDPI), 2023-09) Mehta, A; Serventi, Luca; Kumar, Lokesh; Torrico, Damir
With the growing demand for sustainable practises, the food industry is increasingly adopting circular economy approaches. One example is recycling the symbiotic culture of bacteria and yeast (SCOBY) used in kombucha fermentation to create value-added products. However, consumer acceptance of such novel products remains unclear. To address this, the present study examined consumer attitudes towards ice cream made with SCOBY as an ingredient and how this affected their intention to consume it. Drawing on the theory of planned behaviour (TPB) and additional constructs such as emotions and food neophobia, an online survey was conducted with New Zealand consumers (N = 170). Results showed that the TPB constructs significantly predicted the intention to consume SCOBY ice cream. Moreover, by adding emotions to the constructs, the model’s explanatory power was enhanced. Attitudes, subjective norms, and emotions were the main predictors of intention, which in turn was found to be the main predictor of behaviour. Participants’ beliefs about the safety and taste of SCOBY ice cream were significantly correlated with their intention and behaviour, as were the opinions of nutritionists/dietitians, friends, and family. The model accounted for 21.7% of the variance in behaviour and 57.4% of the variance in intention. These findings can be used to plan marketing strategies related to waste-to-value-added products such as SCOBY ice cream.
Trypsin inhibitor content of New Zealand grown pea cultivars : A thesis submitted in partial fulfilment of the requirements for the degree of Master of Science at Lincoln University, Canterbury, New Zealand
(Lincoln University, 1996) Howard, Toni Mary
The purpose of this study was to determine various components of field pea cultivars grown in Canterbury , New Zealand. Proximate analysis was used to measure the nutritional composition of these pea variaties. Of particular interest were the antinutritional components, trypsin inhibitors Comparison of different techniques to extract and quantify trypsin inhibitors, and purification of various trypsin inhibitor isoforms were the major focus of this study. The effect of location variation was also investigated to determine if environmental conditions significantly altered the composition of the pea cultivars. The proximate composition (protein, fibre, fat and ash content) of thirteen pea cultivars resulted in significant differences (p<0.05) between all cultivars. In addition the effect of growing four pea cultivars at three different locations exerted a significant (p<0.05) effect on the protein, fibre and ash content of all cultivars studied. Measurement of trypsin inhibitor content (using the Kakade et al,(1974) enzymic assay), of pea cultivars grown at Lincoln varied significantly (p<0.05). The majority of cultivars contained less than 2 mgTI/g pea flour, which is the maximum level soon be allowed for export to the European Union. The range of trypsin inhibitor content of these New Zealand grown peas was 0.32 - 2.57 mgTI/g pea flour. Location also significantly (p<0.05) altered the trypsin inhibitor content of the four pea cultivars grown at Chertsey and Methven. The amount of trypsin inhibitor in peas was also determined using ELISA. The results from ELISA correlated well (R²=0.82) with the traditional Kakade (et al, 1974) enzymic assay. Five proteinase inhibitors were purified from the pea extracts firstly by gel filtration and then by ion exchange chromatography. Isolation of two peaks IV and V had mobility on SDS-PAGE equivalent to 29-30 kDa. As other researchers have suggested trypsin inhibitors can bind together, it is possible the trypsin inhibitor molecules in the isolated fractions may be associated in multiple units. Isoelectric focusing of eight pea cultivars identified between three and nine isoforms of trypsin inhibitor. Generally, cultivars that contained high levels of trypsin inhibitor also contained a large number of isoinhibitors. A maximum of nine trypsin isoinhibitors were detected in two cultivars (Birte and Prussian Blue) grown at Chertsey, however only three isoinhibitors were detected in the two maple pea varieties measured. The range of isoelectric points obtained from the inhibitors of pea extracts were from pI 4. 7-9 .4.
Effect of leaf rust infection on chloroplast protein synthesis in leaves of barley (Hordeum vulgare cv. Triumph) : A thesis submitted in fulfilment of the requirements for the degree of Master of Science in the University of Canterbury [Lincoln College]
(Lincoln College, University of Canterbury, 1987) Ooi, Khai Hin
In this work chloroplast protein synthesis was examined in 7 day old leaves of barley (Hordeun vulgare cv. Triumph) infected with 2 isolates of barley leaf rust (Puccinia hordei Otth PS and 65) . At 18 hours after inoculation a decrease in protein synthesis in the chloroplast accompanied the compatible reaction . In contrast, the incompatible reaction showed an increase in protein synthesis. Similar decreases in protein synthesis with compatible host-pathogen combinations and increases with incompatible combinations have been reported in the literature. This indicates a connection between host response to infection and protein synthesis. The protein synthesis inhibitors chloramphenicol and cycloheximide were used to distinguish between chloroplastically and cytoplasmically synthesized chloroplast proteins. The results indicated that most of the affected proteins were synthesized by the chloroplast. Analysis of the polypeptides on gradient SDS-PAGE gels showed major changes at 26 kd, 32 kd, 90-120 kd and 140-180 kd. The polypeptides in these regions are thought to be associated with photosynthesis and transcriptional and translational control. Such changes would explain observations of alterations in activities of the respiratory enzymes during the later stages of infection. This suggests that contribution of the chloroplast to host response at the early stages may be in the form of energy for production of resistance promoting factors.
Effect of rendering on meat meal protein quality and in vitro assessment of meat and blood meal protein quality : A thesis submitted in partial fulfilment of the requirements for the degree of Master of Applied Science in the University of Canterbury [Lincoln College]
(Lincoln College, University of Canterbury, 1988) Dawson, Christopher O.
The different types of rendering processes and the conditions each type applies to raw material to produce meal and tallow are reviewed. The effect different types of raw material have on the composition and nutritive value of meat meals is also reviewed. Some of the likely beneficial and detrimental effects of the rendering process are discussed and the nutritional effect of rendering using the traditional batch dry renderer was compared with the effect of a semi continuous wet (Centrimeal) process and the MIRINZ low temperature wet rendering (ML TR) system. The comparative nutritive values were determined using rat nitrogen balance trials when the test sample was fed as the sole source of protein (8%) in a semi synthetic diet which was nutritiously adequate in all other respects. Both the Centrimeal and MLTR processes produced better quality meal and had significant advantages over the traditional batch dry method of rendering. In addition individual amino acid digestibilities determined using both the ileal digesta of rats and faeces of precision fed intact cockerels confirmed the nitrogen balance results. Jn vitro methods for determining soluble nitrogen as an index of in vivo determined protein quality were reviewed. Two methods, a pepsin and pronase method were evaluated for both meat and blood meals. Good correlations with in vivo values were achieved for meat meals using both methods although changes to the methods used were suggested. Blood meals in vitro values generally did not correlate well with in vivo values. It was thought that part of the poor correlation was due to poor in vivo values. An alternative method for determining in vivo values for blood meals using rat nitrogen balance trial diets supplemented with iso leucine was shown to be more effective than supplementing the semi-synthetic diets with albumin. Quick in vitro digestibiliy methods for evaluating in vivo were reviewed covering the pH drop and pH-stat methods. The pH-stat method was used on 4 progressively heat treated meals and showed excellent correlations with in vivo values after digesting for 10 minutes using Alcalase enzyme and correcting for base line drift. The results of these experiments show that the pH-stat method used is capable of quickly and accurately evaluating heat damage for the same type of sample.
Physicochemical characteristics, techno-functionalities, and amino acid profile of Prionoplus reticularis (Huhu) larvae and pupae protein extracts
(MDPI, 2023-01) Kavle, RR; Nolan, PJ; Bekhit, AE-DA; Carne, A; Morton, James; Agyei, D
The amino acid profile, techno-functionalities (foaming stability/capacity, emulsion stability/capacity, solubility, and coagulation), and physicochemical characteristics (colour, particle size, surface hydrophobicity, Fourier-transform infrared spectroscopy, and differential scanning calorimetry) of protein extracts (PE) obtained from Prionoplus reticularis (Huhu grub) larvae (HLPE) and pupae (HPPE) were investigated. Total essential amino acid contents of 386.7 and 411.7 mg/g protein were observed in HLPE and HPPE, respectively. The essential amino acid index (EAAI) was 3.3 and 3.4 for HLPE and HPPE, respectively, demonstrating their nutritional equivalence. A unique nitrogen-to-protein conversion constant, k, and the corresponding protein content of the extracts were 6.1 and 6.4 and 72.1% and 76.5%, respectively. HLPE (37.1 J/g) had a lower enthalpy than HPPE (54.1 J/g). HPPE (1% w/v) exhibited a foaming capacity of 50.7%, which was higher than that of HLPE (41.7%) at 150 min. The foaming stability was 75.3% for HLPE and 73.1% for HPPE after 120 min. Both protein extracts (1% w/v) had emulsifying capacities that were 96.8% stable after 60 min. Therefore, protein extracts from Huhu larvae and pupae are of a good nutritional quality (based on their EAAI) and have techno-functional properties, such as foaming and emulsification, that afford them potential for certain food technology applications.

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