This site is a post-script to my teaching page at the University of Guelph Growth & Structure of Meat Animals and indexes my research since retirement at the end of 2006. One experiment leads to another for the curious scientist – why should retirement terminate curiosity?
Meat toughness can be measured with cylindrical cores of meat cut in a shear press. But a whole roast of beef is a far more complex system, with various layers affected to differing degrees by cooking, as shown in this research using a fluorescence penetrometer.
It is widely known among meat scientists that natural acidification causes meat to become progressively more pale. This is essential to give a bright appearance to beef, but may become a problem if it goes too far in pork and poultry meat. The experiments reported in this paper explain how acidification changes the optical properties of meat.
The fact that you are reading this proves that the internet has enhanced the way we communicate science. Electronic publishing of science produced some major changes, a few of which are documented here.
Plants store sugars as starch, and starch granules are a major food ingredient. It is widely known among food scientists that starch granules appear with a Maltese cross when viewed with a polarizing microscope. Under certain conditions, the quadrants of the cross may light up with diagonal pairs of colours. This research explains why.
Sometimes waterfalls on the Niagara Escarpment are surrounded by petrified mosses. This research shows how lime is deposited on mosses.
In the age of the internet, we all take popular science and the international communication of science for granted – but how did these important ideas get started?
Our remote ancestors ate meat, and so do most of us now. Meat has been around for the whole of our history – in wars, religions, language, literature, laws and technology. Here are some of the main points.
Have you ever seen flickering patterns of light on the forest floor, or on the bottom of a swimming pool? What would you see if you were very small and you could swim under mosses in a waterfall?
Rainbow colours of oil on water, and rainbow colours on beetles and butterfly wings are a familiar sight, and the causes are well known . But what causes rainbow colours on meat?
Water seeping through limestone makes a major contribution to streams and rivers feeding into the Great Lakes of North America. Scientists around the World are watching the levels of carbon dioxide in the atmosphere, but levels are much higher in the soil, where it is produced by microbial respiration. Carbon dioxide dissolves in groundwater, but blows into the atmosphere when the groundwater emerges into streams. What buffering will vast quantities of slowly moving groundwater give us against rising carbon dioxide levels in the atmosphere? How might changes in groundwater acidity and temperature affect our fish? Nobody knows right now, which is why we need the baseline measurements in this research paper.
This shows that iridescence in tuna muscle is just like iridescence in beef – most likely caused by reflective interference from A-bands.
Preliminary research for adapting on-line prediction methods to camel meat, including polarized-light interferometry.
232. Swatland, H.J. 2014. Reflectance versus transmittance: the effects of light scattering on red colorants (carmine, Amazonian red annatto, and Peruvian cochinilla rojo and rosada) in biological, textile and museum science. Color Research and Application. 39: 599-606.
From textile fibers to biological samples it looks as if light scattering in the sample has more effect on colorimetry than the way in which the color is measured.
233. Swatland, H.J. 2016. Interference colorimetry of starch granules. Color Research and Application 41: 352-357. The subjective evaluation of interference colours is a standard method of identifying minerals in rock sections – but the reference charts are highly variable because they use colorants in an attempt to simulate what happens when sinusoidal waves interact with the spectral sensitivities of the human eye. Being somewhat reluctant to challenge a standard method in mineralogy, I chose to work on starch granules and to solve an ancient problem in polarized light microscopy. Jonathan Pereira, one of the great pioneers in pharmacology, reported in 1843 that starch granules exhibited a quadrant of diagonally paired interference colors when viewed under a polarizing microscope fitted with a selenite compensator. Research showed that the weighted-ordinate method of colorimetry could be used to measure this phenomenon and that, as expected, it was a function of the diameter of the starch granules. OK – this research will get ignored by mineralogists, but it satisfies my curiosity.
234. Swatland, H.J. 2016. Starch granules in polarized light, following Pereira into the ultraviolet. Quekett Journal of Microscopy 42: 601-609. This research challenges some current beliefs held by food scientists and shows that the birefringence of starch granules is caused primarily by straight chains of amylose.
235. Swatland, H.J. 2017. Colored clays in a groundwater stream, correlating fiber-optic reflectance with electrical impedance. Hydrology Current Research 8:283. Wikipedia suggests that the coloured clays on the Niagara Escarpment might be caused by acid groundwater. No evidence of this was found, whereas a combination of palaeontology and fibre-optic reflectance indicated that clay colour is determined by shale colour, and that shale colour may be determined by aerobic versus anaerobic conditions at the time of sediment formation.
236. Swatland, H.J. 2017. A review of microcolorimetry for textile, food, dental and optoelectronic industries. Asian Journal of Engineering and Technology 5: 140-151 Macroscopic colorimetry is an essential tool for color matching in many industries, but microcolorimetry has been neglected. From individual fibers in complex textile pattern to the dental fillings in our mouths – their colors can all be measured.
237. Swatland, H.J. 2017. On wetting Muscovy glass and a peacock feather, following Robert Hooke to investigate the colourimetry of meat iridescence. Quekett Journal of Microscopy 43: 125-130. As the first great microscopist discovered, multilayer interference survives under water while surface diffraction does not. Hooke’s discovery is used to show that iridescence in meat is not from surface diffraction, but from multilayer interference. The multilayers are the sarcomere discs discovered by Bowman (another great microscopist).
238. Swatland, H.J. 2018. Iridescence in cooked venison – an optical phenomenon. Journal of Nutritional Health and Food Engineering. 8(2): 105-108. This shows that iridescence in venison is just like iridescence in beef and tuna – most likely caused by reflective interference from A-bands because it is visible under water..
239. Swatland, H.J. 2018. Colourimetry of chromatic aberration. Quekett Journal of Microscopy. 43: 307-314. The weighted-ordinate method of colourimetry was used to detect chromatic aberration in a wide range of microscopes. Extremes of microscope conditions had minimal effect on colourimetry – thus showing there is no reason why colourimetry cannot be used with light microscopes. In primitive microscopes, chromatic aberration is made worse by interference effects. LED illuminators do not interfere with colourimetry.
240. Swatland, H.J. 2019. Fluorometry of natural latex from Maclura pomifera. Earth and Environmental Science Research and Reviews. 2 (1). Maclura pomifera is a small tree that produces rot-resistant wood and is found at the northern edge of its range on the Niagara Escarpment. It has a fascinating geological history, it seems to have worked its way north when South America became linked to North America by plate tectonics and volcanic activity. Ancient animals such as the giant ground sloth may originally have spread its seeds, but it was widely planted in recent times to produce rot-resistant fence posts and, perhaps, rot-resistant wood for water mills? It produces a strange fruit called an Osage orange, which often dries to produce a bright green ball, something like a pineapple in botanical structure. The fruit seems to resistant rotting because of its high latex content. Latex is often fluorescent so, of course, I had to measure it.
241. Swatland, H.J. 2019. Colourimetry of iridescent muscle fibres. Quekett Journal of Microscopy. 43:357-362. The research gets one step closer to finding how light is scattered when passing along the long axes of muscle fibres. A single dominant interference peak from A-band reflectance gives a bright metallic colour, while fibres with multiple peaks have less chromatic intensity and their colour coordinates converge on the central white part of the CIE diagram.
242. Swatland, H.J. 2019. Signal analysis of optical interference in relation to colorimetry for measurements made along individual myofibers in cooked beef. Asian Journal of Agriculture and Food Science 7: 107-113. The discovery made in the previous paper (241) was that iridescence is a special case of light scattering along myofibers – one or a small number of reflective A bands create a metallic color, while numerous reflective A bands give rise to scattering with very little color. But colors were still being judged subjectively. This research removed the subjective element and signal analyses of interference peaks were correlated directly with weighted-ordinate color coordinates of the same spectra.
243. Swatland, H.J. 2020. Light penetration through shallow flowing water, comparing the effects of surface lenses in laminar flow with bubbles added in turbulent flow. Earth & Environmental Science research & Reviews 3. (1)
The deep penetration of blue light through great depths in the sea is well known to divers, but what happens in very shallow freshwater streams? What wavelengths for photosynthesis reach the aquatic mosses in shallow water?
244. Swatland, H.J. 2020. Reflective layers in the fruit of Maclura pomifera – bright enough to attract a Giant Ground Sloth? Quekett Journal of Microscopy 43: 511-514. There is a popular but almost unprovable idea that Giant Ground Sloths used to eat the fruits and distribute the seeds of the Osage orange. But it is possible to explain the sometimes amazing bright green surface of the fruit.
Most colorimeters have an aperture of several square centimeters, but they are often used on samples with a variegated appearance like the grain patterns on wood – light yellowish lines separated by darker brown lines. How are variegated samples integrated to give a simple set of chromaticity coordinates? This research on exotic woods with a wide range of grain pattern and color (each measured with different methods) showed a connection between grain patterns and CIE x.
246. Swatland, H.J. 2020. Microscopy of static and moving bubbles and leaf shadows. Quekett Journal of Microscopy 43:713-716. If terrestrial plant life evolved in shallow water, chlorophyll might have evolved to use the red light not strongly attenuated by bubbles and surface lensing of water.
247. Swatland, H.J. 2021. Connective tissue fluorescence in venison measured with an ultraviolet light-emitting diode. Biomedical Journal of Scientific & Technical Research 35(4)-2021. A lot of work went into developing a UV probe to detect connective tissue in beef. It worked well, especially in populations without cold-shortening. However, the technology went nowhere because it required an arc lamp to generate UV light – high voltage start-up circuits and fragile arcs were difficult to engineer for a commercial abattoir. But now there are inexpensive UV LEDS – low voltages, extended working life and not fragile. To make the research interesting for myself, I decided to measure fluorescence in wild versus farmed venison. The unexpected benefit was a jump forward in understanding colorimetry of venison.
248. Swatland, H.J. 2021. An explanation of subsurface optical pathways through food myosystems and their effect on colorimetry. Asian Journal of Agriculture and Food Sciences. 9: 143-157. Finally, there now appears to be some consensus that light scattering in meat, poultry and fish muscle affects color measurements. Original data from optical experiments on light scattering in myosystems were re-analyzed to calculate CIE chromaticity coordinates.
An invited abbreviated version of #226 above, for a commercial publication.
An invited conference presentation guessing how basic science, from sensory perception, through x-ray diffraction for the effects of pH on interfilament separation, to interferometry in meat, might be used to grade meat.
130. Swatland, H.J. 2012. Developing new technology for measuring camelid meat quality. 3rd Conference of the International Society of Camelid Research and Development, Sultan Qaboos University, Muscat, Sultanate of Oman. Keynote Presentations, p. 52-62.
An invited conference presentation on how on-line evaluation of meat might be applied for the grading of camel meat.
An invited conference presentation on how the terminology of US meat cuts may have developed linguistically from Ancient Greece to the present day, via Norse and Old English and French.
An invited conference presentation on how light scattering affects meat colorimetry.
133. Swatland, H.J. 2012. Posibilidades futuras de los sensores en línea para productos cárnicos. Herramientas Tecnológicas Aplicadas a Calidad y Diferenciación de Carne. Pp. 7-13. Compilador, Dra. Gabriela Grigioni - Ing. M.Fernanda Paschetta Área de Análisis Físicos y Sensoriales, Instituto de Tecnologia de Alimentos, INTA
A review of how on-line evaluation of meat might be used in South America.
134. Swatland, H.J. 2013. Prospects for online grading of camel meat yield and quality. In Camel meat and Meat Products (I.T. Kadim, O. Mahgoub, B. Faye & M.M. Farouk, editors), CAB International, Oxford. pp. 85-97.
A book chapter expanding on how on-line evaluation might be used for camel meat.
Explains the histology of muscle growth in meat animals.
136. Swatland, H.J. 2014. Groundwater streams running over clay on the talus slope of the Niagara Escarpment (Canada): an overview with ecological implications. In: S.M. Adelana, editor, Groundwater: Hydrochemistry, Environmental Impacts and Management Practices, Nova Publishers, Hauppauge, NY.
Cold groundwater in a river bed creates suitable conditions for the spawning of brook trout (Salvelinus fontinalis). In some locations along the Niagara Escarpment, groundwater discharged from a primary aquifer may run, exposed to the atmosphere, down a slope of clay into the river. At other locations, the flow above clay may be within the overburden and only exposed at odd sites, such as the stream vent described in this chapter. In exposed streams, travertine deposited by the degassing of calcium-rich groundwater after passing over clay is darker than upstream deposits. Spectrocolorimetry of travertine, clays and shale, and electrical impedance of clays were used to gather supporting information. Ecological sampling showed a rich river fauna in the study area, mostly associated with pristine water.
A variety of optical methods were used to investigate the flicker patterns of light in small waterfalls and their splash zones. Flicker patterns are important for the photosynthesis of plants in and around small waterfalls, especially mosses. In a forest environment, the intensity of incident light was increased when the sky was clouded and when deciduous trees lacked leaves. Light penetrated deeply into waterlogged splash zones by a series of reflections from living moss leaves, as shown by using polarized light to detect Fresnel reflectance. Penetration was also high through dead, brown moss below the living moss, but this was because only the walls of empty cells remained. Flicker patterns in flowing water originated from surface lensing and bubbles, and were measured using optical fibers. In the splash zone, flickering was increased by shadowing from moving moss leaves. Shadowing by bubbles was estimated from transmittance measurements made with a microscope spectrophotometer. Shadowing from large bubbles was mainly from the Becke line (refractive index boundary) around the bubbles. Small bubbles cast strong shadows if the Becke line occluded the central axis of the bubble.
138. Swatland, H.J. 2018. Polarized light microscopy of moss leaves encrusted with calcium carbonate. In Mosses. Ecology, Life Cycle and Significance. Editors: O. Pokrovsky et al. Chapter 12. P 275-287.A review of studies on calcium carbonate deposition on mosses to produce travertine on the Niagara Escarpment. My conclusion is there is nothing special about the moss – it grows fast and can keep pace with petrification, eventually give rise to massive layers of travertine.
139. Swatland, H.J. 2018. Fascinating iridescence. Canadian Meat Science Association website. A summary of arguments to support multilayer interference from sarcomere discs.
140. Swatland, H.J. 2019. Letter to the editor: Marsh and Bendall – pioneers in muscle biochemistry and meat science. Meat Science 151: 60-62. This letter contains lecture notes by James Bendall in 1982 explaining how he and Bruce Marsh discovered calcium ions control muscle contraction and relaxation.
Colorimeters typically illuminate samples laterally so that the main vertical photometry pathway avoids specular surface reflectance such as surface wetness. For microscopy, this can be copied by using lateral fiber optic illumination, but this requires a considerable gap between the sample and the objective lens.
This is not a text-book but a series of personal observations and arguments to support the idea that meat consumption culture can give us a new perspective on meat science, and vice versa.
TRANSLATIONS OF BOOKS
1. H.J. Swatland. Estructura y desarrollo de los animales de abasto. Pedro Ducar Maluenda (Translator). Vísceras y subproductos. Los tejidos conjuntivos de la canal. Estructura comercial de la canal. Distribución anatómica de los músculos de la canal. Estructura y propiedades de la carne. Diferenciación de las fibras musculares y relaciones neuromusculares. Base celular del crecimiento muscular postnatal. Crecimiento y desarrollo animal. Conversión del músculo en carne. Editorial Acribia.
ERRATA. The origin of the universe was probably the consequence of a divine mistake, so the mistakes in my work should be viewed in their proper light, as small echoes of the primaeval big bang.
228. The colour figure of iridescence is for iliocostalis not iliopsoas, but identical iridescence can be seen in iliopsoas, so this error does not worry me too much.
234. On page 602, corrections made to the final copy did not reach the printer – straight chains have 1-4 linkage, while branch points have 1-6 linkage.