title: Investigation of anti-fouling processing aids in the primary evaporation of whey permeate

authors: Harrison, Dylan

subjects: whey permeate

abstract: The production of lactose via the concentration of whey permeate is an important process in the dairy industry. Hautapu dairy factory, owned by Fonterra Cooperative Group, process milk into a range of dairy-based products including; Cheese, Milk Protein Concentrate and Lactose. This project was focused around reducing fouling during the evaporation of whey permeate for the production of lactose powder. As whey permeate is heated in evaporators, mineral salts precipitate and accumulate onto the stainless steel heat exchange surfaces. This layer of mineral scale, known as fouling, greatly reduces the amount of heat transfer used for evaporating the whey permeate. Once the fouling gets to a point where it is no longer achievable to reach the concentrated solids target, the evaporator is shut down and cleaned with chemicals to remove the scale build up.

To decrease the amount of scale build up, a process aid is added to the whey permeate. This process aid A , or PAA, is a polyphosphate that when added to the feed stream gives longer run times. This project was aimed at establishing the chemistry behind the inhibiting abilities of PAA and its interaction with whey permeate. It is known that PAA acts as a complexing agent with calcium when it is added to the permeate stream which prevents it from forming calcium phosphate, the main source of fouling.

In the course of the research, it was fortuitously discovered that PAA works very inefficiently as an inhibitor in whey permeate because of its ability to form an insoluble salt with free calcium ions. The consequence of this was that high calcium levels in whey permeate lead to PAA precipitating out of solution rendering it an ineffective anti-fouling agent to prevent further scale build up. As a result of this, alternative inhibitors were considered and tested for their calcium tolerance and calcium phosphate inhibiting properties. From these considerations, carboxymethyl inulin was regarded as the most favourable replacement candidate for PAA. This resulted in plans being set down for a future industrial trial involving the carboxymethyl inulin.

text: Investigation of anti-fouling processing aids in the primary evaporation of whey permeate The production of lactose via the concentration of whey permeate is an important process in the dairy industry. Hautapu dairy factory, owned by Fonterra Cooperative Group, process milk into a range of dairy-based products including; Cheese, Milk Protein Concentrate and Lactose. This project was focused around reducing fouling during the evaporation of whey permeate for the production of lactose powder. As whey permeate is heated in evaporators, mineral salts precipitate and accumulate onto the stainless steel heat exchange surfaces. This layer of mineral scale, known as fouling, greatly reduces the amount of heat transfer used for evaporating the whey permeate. Once the fouling gets to a point where it is no longer achievable to reach the concentrated solids target, the evaporator is shut down and cleaned with chemicals to remove the scale build up.

To decrease the amount of scale build up, a process aid is added to the whey permeate. This process aid A , or PAA, is a polyphosphate that when added to the feed stream gives longer run times. This project was aimed at establishing the chemistry behind the inhibiting abilities of PAA and its interaction with whey permeate. It is known that PAA acts as a complexing agent with calcium when it is added to the permeate stream which prevents it from forming calcium phosphate, the main source of fouling.

In the course of the research, it was fortuitously discovered that PAA works very inefficiently as an inhibitor in whey permeate because of its ability to form an insoluble salt with free calcium ions. The consequence of this was that high calcium levels in whey permeate lead to PAA precipitating out of solution rendering it an ineffective anti-fouling agent to prevent further scale build up. As a result of this, alternative inhibitors were considered and tested for their calcium tolerance and calcium phosphate inhibiting properties. From these considerations, carboxymethyl inulin was regarded as the most favourable replacement candidate for PAA. This resulted in plans being set down for a future industrial trial involving the carboxymethyl inulin.

year: 2009

title: Understanding the role and impact of introduced honey bees in a submontane indigenous forest ecosystem

authors: Nepia, Rachel E.

subjects: pollination

abstract: New Zealand’s apiculture industry is the fastest growing in the world, expanding in agricultural landscapes, as well as in native ecosystems. While this has obvious benefits for economy and industry, the impacts on sustainability of native ecosystems are less easy to discern. Honey bees (Apis mellifera) have a suite of potential impacts, both positive and negative, on native plants and flower visitors in native ecosystems. This research aimed to investigate the impact of managed introductions of Apis mellifera in native forest dominated by Weinmannia racemosa and Ixerba brexioides, two native forest trees used extensively for monofloral honey production in New Zealand. Research focused on three key areas: 1) timing and availability of floral nectar resources; 2) impacts on plants, particularly I. brexioides and W. racemosa; and 3) impacts on invertebrate flower visitor communities. 
Availability of floral nectar resources from I. brexioides and W. racemosa was assessed using a combination of nectar collection and phenology data. Pollination potential of honey bees was assessed using video surveillance and effects on seed set of I. brexioides and W. racemosa were observed using exclusion experiments. Community-level effects on invertebrate flower visitors were assessed using collection of flower visitors and assessment of community data using multivariate and other statistical approaches.
Timing and availability of floral nectar resource showed extreme variation between annual cycles. Nectar sugar production was lowest during a hot, dry summer compared with a cooler, wetter summer, in terms of both sugar production per flower and flower production per tree. At a landscape scale, this can have serious flow-on effects for foraging nectar-feeders, and hence for seed set of flowering plants.
Video surveillance showed that suitability of different flower visitors for pollination of I. brexioides and W. racemosa differed. For W. racemosa all groups of flower visitors contacted reproductive structures, allowing for successful pollination. However for I. brexioides, pollination potential was greatest for birds, beetles and native bees and least for spiders, wasps, ants and honey bees. Seed set for I. brexioides was highest at pest-proof fenced sites and lowest at high hive density sites, whereas W. racemosa seed set was highest at high hive density sites, and lowest at low density sites. Weinmannia racemosa had lowest levels of pollen limitation at sites of high hive density. The combination of W. racemosa responses at the high hive density site suggest that small-flowered species, such as W. racemosa, have the potential to benefit from increased pollination success in areas where honey bees are frequent visitors.
Community analysis showed differences in flower visitor communities between sites with high and low honey bee hive density. Honey bees were the key species contributing to differences between high and low hive density sites. Diversity of insect flower visitors was higher at low hive density sites. Network analysis highlighted structural differences in networks between high and low hive density sites in terms of connectance, nestedness, and species-level indices. High and low hive density sites had a similar number of species that were native and non-native, but high hive density sites had more frequent interactions with non-natives, and 45 % of those interactions were from honey bees.
Pilot studies investigating methods for studying plant-pollinator interactions highlighted a need to tailor methods of pollen isolation to fit the research question, i.e. whether research is focused on pollination interactions or diet-related questions. Comparison of methods for understanding plant-pollinator interactions concluded that identification of pollen by microscopic means identified a greater breadth of plant-pollinator interactions than that identified by field observations alone. However, DNA-based methods of pollen identification have the potential for even greater specificity, cost-effectiveness, and answering a range of questions not possible with traditional methods. 
Analysis and findings from this research support a case indicating that honey bees can affect seed set of native plants, and communities of invertebrate flower visitors in a number of ways. Prevention of permanent changes to flower visitor communities should be prioritised by preserving large areas of intact native forest where low levels of fragmentation create refuges for native flower visitors. Estimates of annual sugar production for I. brexioides and W. racemosa call attention to the need to build greater flexibility into legislated stocking rates in native forest, to minimise competitive effects on native flower visitors during low production years. Developing these measures will build sustainability into New Zealand models of apicultural practise, ensuring longevity of honey operations and protection of native ecosystems.

text: Understanding the role and impact of introduced honey bees in a submontane indigenous forest ecosystem New Zealand’s apiculture industry is the fastest growing in the world, expanding in agricultural landscapes, as well as in native ecosystems. While this has obvious benefits for economy and industry, the impacts on sustainability of native ecosystems are less easy to discern. Honey bees (Apis mellifera) have a suite of potential impacts, both positive and negative, on native plants and flower visitors in native ecosystems. This research aimed to investigate the impact of managed introductions of Apis mellifera in native forest dominated by Weinmannia racemosa and Ixerba brexioides, two native forest trees used extensively for monofloral honey production in New Zealand. Research focused on three key areas: 1) timing and availability of floral nectar resources; 2) impacts on plants, particularly I. brexioides and W. racemosa; and 3) impacts on invertebrate flower visitor communities. 
Availability of floral nectar resources from I. brexioides and W. racemosa was assessed using a combination of nectar collection and phenology data. Pollination potential of honey bees was assessed using video surveillance and effects on seed set of I. brexioides and W. racemosa were observed using exclusion experiments. Community-level effects on invertebrate flower visitors were assessed using collection of flower visitors and assessment of community data using multivariate and other statistical approaches.
Timing and availability of floral nectar resource showed extreme variation between annual cycles. Nectar sugar production was lowest during a hot, dry summer compared with a cooler, wetter summer, in terms of both sugar production per flower and flower production per tree. At a landscape scale, this can have serious flow-on effects for foraging nectar-feeders, and hence for seed set of flowering plants.
Video surveillance showed that suitability of different flower visitors for pollination of I. brexioides and W. racemosa differed. For W. racemosa all groups of flower visitors contacted reproductive structures, allowing for successful pollination. However for I. brexioides, pollination potential was greatest for birds, beetles and native bees and least for spiders, wasps, ants and honey bees. Seed set for I. brexioides was highest at pest-proof fenced sites and lowest at high hive density sites, whereas W. racemosa seed set was highest at high hive density sites, and lowest at low density sites. Weinmannia racemosa had lowest levels of pollen limitation at sites of high hive density. The combination of W. racemosa responses at the high hive density site suggest that small-flowered species, such as W. racemosa, have the potential to benefit from increased pollination success in areas where honey bees are frequent visitors.
Community analysis showed differences in flower visitor communities between sites with high and low honey bee hive density. Honey bees were the key species contributing to differences between high and low hive density sites. Diversity of insect flower visitors was higher at low hive density sites. Network analysis highlighted structural differences in networks between high and low hive density sites in terms of connectance, nestedness, and species-level indices. High and low hive density sites had a similar number of species that were native and non-native, but high hive density sites had more frequent interactions with non-natives, and 45 % of those interactions were from honey bees.
Pilot studies investigating methods for studying plant-pollinator interactions highlighted a need to tailor methods of pollen isolation to fit the research question, i.e. whether research is focused on pollination interactions or diet-related questions. Comparison of methods for understanding plant-pollinator interactions concluded that identification of pollen by microscopic means identified a greater breadth of plant-pollinator interactions than that identified by field observations alone. However, DNA-based methods of pollen identification have the potential for even greater specificity, cost-effectiveness, and answering a range of questions not possible with traditional methods. 
Analysis and findings from this research support a case indicating that honey bees can affect seed set of native plants, and communities of invertebrate flower visitors in a number of ways. Prevention of permanent changes to flower visitor communities should be prioritised by preserving large areas of intact native forest where low levels of fragmentation create refuges for native flower visitors. Estimates of annual sugar production for I. brexioides and W. racemosa call attention to the need to build greater flexibility into legislated stocking rates in native forest, to minimise competitive effects on native flower visitors during low production years. Developing these measures will build sustainability into New Zealand models of apicultural practise, ensuring longevity of honey operations and protection of native ecosystems.

year: 2020

title: Report on the bicultural symposium at conference

authors: Masters-Awatere, Bridgette

subjects: Maori

abstract: Kia ora koutou. I decided to submit the current paper as a way to say thank you to the large group of people in attendance at the bicultural stream at the national conference in late August that was held at Waikato University. It was their continued presence and participation that served as a catalyst and motivator for this paper. I'm conscious that while there was a large number of people in the symposium, there were other streams occurring at the same time, so I thought giving an overview of the success of the symposium would be a good way to let people know who the symposium went. However, before talking specifically about the symposium, I'd like to give mention to other events of the day...

text: Report on the bicultural symposium at conference Kia ora koutou. I decided to submit the current paper as a way to say thank you to the large group of people in attendance at the bicultural stream at the national conference in late August that was held at Waikato University. It was their continued presence and participation that served as a catalyst and motivator for this paper. I'm conscious that while there was a large number of people in the symposium, there were other streams occurring at the same time, so I thought giving an overview of the success of the symposium would be a good way to let people know who the symposium went. However, before talking specifically about the symposium, I'd like to give mention to other events of the day...

year: 2007