Reducing Carbon Footprint
Every morning, the milk in your tea leaves a carbon trail. Livestock contributes a large share of greenhouse gases in manure. So how do we strike a balance between our favourite foods and the carbon footprint?
Amlan Kumar Patra from the West Bengal University of Animal and Fishery Sciences recently published a report assessing livestock contribution to carbon footprint across India. He took the data on cattle, buffaloes, sheep, goats, pigs, horse, mules, pony, donkeys, camel, yak and mithun in different states and territories of India from the Indian livestock census reports of Government of India 2012. He considered enteric emissions by the various animals as well as emissions from manure and calculated the total greenhouse gases: equivalent to three lakh Gigagrams of carbon dioxide!
Cattle are the largest producers of methane, buffalo coming as a second. Patra suggests that a change in the pattern of livestock population, adoption of crossbreeding programs and appropriate changes in the feed composition could significantly reduce the greenhouse gas emissions. To avoid impacting milk production, an increase in female cattle population without adding to the male population is also suggested.
Several related factors such as socioeconomic status and culture of the people, as well as the livestock policies of Indian states, make the issue complex. The complexity of the issue involves not just the consumer, but also the producer, including poor farmers whose livelihoods depend on these animals. Patra’s paper brings hope to redefine livestock policies and programmes to a more eco-friendly direction.
Journal of Cleaner Production, 162 : 678-686 (2017)
Buffalo Milk: Microbial Load
Bacteriocin peptide preservative
Milk is an ideal medium for microbial growth. Microbial contamination occurs mostly during storage and transport. Microbes have adapted to survive even in cold storage. Antimicrobials have been used to enhance the shelf life of milk. However, antibiotics have undesirable consequences. One strategy to overcome the problem is to use bacteriocins – small peptides secreted by bacteria to inhibit other species from proliferating.
Scientists from the NDRI, Karnal now report the use of one such bacteriocin, pediocin PA-1, as a biopreservative for buffalo milk. The team first isolated and identified microorganisms from raw buffalo milk. They confirmed that the isolates were Streptococcus spp., Enterococcus spp., Salmonella, Campylobacter (Staphylococcus), Lactobacillus spp., E coli, and Shigella after sequence comparison with a genome database. Light microscopy confirmed the presence of Candida and Aspergillus spp.
For the production of pediocin PA-1, the researchers used lactic acid bacteria, Pediococcus pentosaceus NCDC 273 strain, to ferment cheese whey medium. They estimated the total microbial count of each isolate in the presence of pediocin PA-1 containing medium. For this, they plated raw buffalo milk with varying concentrations of whey medium containing pediocin PA-1. The team determined the activity of pediocin PA-1 by visually scoring the zone of inhibition for each isolate. There was a decreasing trend in the total count of staphylococcus and lactic acid bacteria isolates in pediocin PA-1 containing medium. However, pediocin PA-1 was less effective against coliform bacteria and yeast-mould.
Milk preservation has become obligatory. As a preservative, pediocin PA-1, produced using cheese whey medium, is heat-stable and nontoxic. Useful news for dairy farms.
LWT – Food Science and Tech., 83: 193-200
Srividya K V