Food waste in municipal solid waste

Adhikari et al. (2006) found a correlation between GDP, percentage urban population, municipal solid waste (MSW) generation, and food waste production on a per capita level. MSW generation is well correlated with GDP (correlation coefficient R2 = 0.94) whereas food waste generation demonstrated a lower (R2 = 0.86), but still a valid correlation. Using

Table 13.1 Summary of the wastage estimated for vegetables from the Steenkoppies aquifer

Commodity groups

Production

(T/a)

Total wastage as a % of input

Form

Market

Retail

Consumer

Total

Root & Tubers

49,022.9

24.3

0.7

2.3

1.5

28.8

Vegetables

47,976.6

17.9

4.6

5.5

3.6

31.6

Source: Adapted from Le Roux et al. (2017) these correlations, Adhikari et al. (2006) calculated the urban food waste in South Africa as

5.05 million tonnes in 2005 or 48% of MSW and this is expected to increase to 7.83 million tonnes, or 45% of the total MSW fraction, in 2025 if current waste management practices are maintained (Adhikari et al., 2006).

In 2012, Nahman et al. estimated the cost of household food waste in South Africa at 1.4 million tonnes per annum, at a cost to society of R21.7 billion (approximately US$2.7 billion at 2012 exchange rates1) per annum (Nahman et al., 2012). More recently, there have been an increasing number of waste characterisation studies undertaken by municipalities in South Africa. Unfortunately, few of these waste characterisation studies are comparable, and food waste is still not reported as a separate waste category in most of these studies. The studies that reported food waste as a separate waste category are listed in Table 13.2. The food waste component in these studies varied between 3% in Ekurhuleni and 33% in Nelson Mandela Metropolitan municipality.

Oelofse et al. (2018) published the food waste results of comparable waste characterisation studies from two of the big metropolitan municipalities in the Gauteng Province of South Africa (Oelofse et al., 2018). The results provide an indication of the food waste disposed of to the municipal bin rather than the food waste generated at household level. These results indicated an average weekly food waste disposal rate of 0.69 kg per household in Johannesburg and 0.48 kg per household in Ekurhuleni. The household food waste disposed to landfill in these two municipalities, which are home to 25% of the South African population and

Table 13.2 Food waste percentages reported in waste characterisation studies in South Africa

Municipality

% food waste

Comment

Source

City of Cape Town

8

2011 study covering households only

CoCT IWMP, 2015

City of Tshwane

Kitchen waste from households reported as organic fraction

Komen et al., 2016

Nelson Mandela

Metropolitan

Municipality

33

Random sampling of trucks entering the landfill site. Includes household and commercial waste

Pilusa, 2017

Polokwane

31

Ethekwini

31

Msunduzi

22

Percentage of MSW

McCarthy, 2016

Mbombela

i6

Mangaung

15

Rustenburg

16

Mhlatuze

23

Emfuleni

12

City of Johannesburg

7

Percentage of household waste

Oelofse, Muswema and Ramukhwatho, 2018

Ekurhuleni Metropolitan Municipality

3

contribute 34% to the country’s GDP, amounts to 76,661 tonnes per annum. Since these two studies are not a representative sample of metropolitan municipalities in South Africa, it is not possible to use these results for extrapolation purposes. It is, however, interesting to note that the food waste component of household waste (excluding garden waste) in these two municipalities was 3% in Ekurhuleni and 7% in Johannesburg (Oelofse et al., 2018) in contrast to the predicted 45% ofMSW in 2025 (Adhikari et al., 2006).

Oelofse and Muswema (2018) estimated the food waste from domestic sources in MSW at 2.38 million tonnes per annum in 2011. They have used the food waste generation per income group from Nahman et al. (2012) and applied these to the provincial distribution of the adult population per income group in 2010.

Food waste in informal settlements

Mollatt (2014) investigated food waste flows and food production in Enkanini informal settlement in Stellenbosch using a mixed method approach including transdisciplinary, action research and participatory action research. Food waste collected from participating households was measured as, on average, 9.6 kg per household per week (Mollatt, 2014).

National estimates of food waste and cost

The first attempts to quantify food waste in South Africa beyond MSW were carried out in

2012. Oelofse and Nahman followed a similar approach to that used in the global assessment by Gustavsson et al. (2011), but using the estimated/assumed waste percentages for each commodity group in each step of the food value chain for sub-Saharan Africa and applying this to the South African production figures (Oelofse and Nahman, 2013). The calculated average per annum food waste generation figure for South Africa is reported, as a preliminary finding, at approximately 9.04 million tonnes per annum (Oelofse and Nahman, 2013). The authors caution that this is a highly aggregated result that needs to be verified through primary data collection (Oelofse and Nahman, 2013).

In 2013, Nahman and De Lange estimated the cost of edible food waste along the entire food value chain from agricultural production, post-harvest handling and storage, processing and packaging, distribution (including wholesalers, supermarkets and retailers) and consumption (waste at household level) (Nahman and De Lange, 2013). During their research, the food waste estimates of Oelofse and Nahman (2013) were updated by also accounting for food imports and exports. The new updated estimate of food waste (edible portion) generation in South Africa was 10.2 million tonnes per annum (Nahman and De Lange, 2013). Since the focus of this estimate was on the edible portion of food waste, it can be assumed that this food waste is avoidable. The total cost of the edible portion of food waste throughout the value chain amounts to R61.5 billion per annum (approximately US$7.7 billion at 2013 exchange rates), or 2.1% of the national annual GDP of South Africa (Nahman and De Lange, 2013).

However, there are also costs associated with the inedible portion of food waste, namely opportunity costs that are lost if the waste is not used as input material into other processes, such as composting, bio-energy generation, or the production of animal feed (De Lange and Nahman, 2015). De Lange and Nahman, (2015) therefore developed a methodology for the estimation of opportunity costs associated with the inedible portion of food waste.

A first step in determining the opportunity costs of inedible food waste, was to quantify it. Assuming that 81% of food waste is avoidable (based on Ventour, 2008), De Lange and Nahman (2015) calculated the total food waste in South Africa as 12.6 million tonnes per annum, of which 2.4 million tonnes (19%) are inedible. The full cost of disposing food waste to landfill (including opportunity cost and disposal costs) is estimated as a weighted average cost of R5922 (US$592 at 2015 exchange rates) per tonne. These costs should be compared to the full cost of alternative treatment options to inform decisions regarding waste management options for food waste (De Lange and Nahntan, 2015).

Households’ food waste behaviour

Research on household food wastage and behaviour in South Africa is limited to a few small studies in the City of Tshwane, the broader Gauteng Province and one in Kimberley in the Northern Cape. Ranrukhwatho et al. (2014) reported on a survey covering 50 households in the Mamelodi Township located in the City of Tshwane Metropolitan municipality. The types of food most wasted by the respondents included pap (maize porridge, 58% of respondents), rice (26%) and bread (16%). An electronic survey covering 301 households in the broader City of Tshwane indicated that fruit and vegetables are the most wasted commodities followed by cereals and bread (including pasta, rice cakes and pastries). Dairy products (milk, yoghurt and cheese) were rated in third place followed by meat, poultry, fish and eggs (Oelofse and Marx-Pienaar, 2016). The self-reported wastage (as a percentage of purchase) was more than 30% of fruit and vegetables (31% of respondents), more than 20% of cereals and breads (34% of respondents) and more than 20% of dairy products (27% of respondents) (Oelofse and Marx-Pienaar, 2016).

The finding from the Mamelodi study is interesting from a cultural perspective as the majority of Mamelodi residents are black Africans preparing porridge as a daily staple meal and 90% of respondents indicated that they do not eat fresh fruit and vegetables (Ranrukhwatho et al., 2014). An important finding from this study is the ignorance of respondents about their own household’s food wastage. At the start of the interviews, 82% of respondents indicated that they did not waste food (Ranrukhwatho et al., 2014).

The reported reasons for wasting food are: sell-by date indicated that the product has expired; I was concerned for the health and safety of my family, and I always prepare too much; food residues; and falling for special offers (Ranrukhwatho et al., 2014; Oelofse and Marx-Pienaar, 2016). This result suggests that household food waste behaviour may be very similar to that of households in developed countries (Oelofse and Marx-Pienaar, 2016).

Marx-Pienaar and Erasmus (2014) found that bulk packs of fresh produce are preferred by nearly 70% of the 560 respondents. This preference transpired as one of the prominent causes of food waste (Marx-Pienaar and Erasmus, 2014). It is reported that 45% of respondents who purchased smaller quantities did so to avoid unnecessary wastage. Despite planning fresh produce purchases in advance (66.54%), 44.05% of respondents are reported to waste fresh produce due to slow consumption while nearly 40% admitted over purchasing when prices are low. Attractive displays are also identified as temptations that result in over purchasing (33.77%) which in turn increases wastage. This study also reported a general ignorance about sustainable disposal practices for food waste, with less than 25% of respondents recycling food waste through composting (Marx-Pienaar and Erasmus, 2014).

The consumer demand for visually appealing produce results in fresh produce with slight blemishes, but perfectly suitable for use in cooked dishes, to be discarded as waste by retailers (Marx-Pienaar and Erasmus, 2014). The consumer’s perceived entitlement to superior quality produce is a critical area of concern that requires intervention if food waste is to be reduced. Another concerning finding by Marx-Pienaar and Erasmus (2014) is that almost

60% of respondents were ignorant about the climate change impacts of food wastage, not realising that food waste also generates greenhouse gases during decomposition.

Ramukhwatho (2016) conducted face-to-face interviews with 210 households in the City of Tshwane from five suburbs targeting different socio-economic groups. Participating households were requested to separate their food waste and weigh it on a weekly basis over a three-week period in order to measure actual food waste generation at household level. On average, respondents wasted 6 kg of food per week. A statistically significant difference was reported between income groups, with low-income households wasting more food than middle-income households and high-income households wasting the least food by weight (Ramukhwatho et al., 2016). Disposal to the municipal bin is the main waste management option used by 83% of respondents, while 14% of respondents feed their food waste to pets and the remaining 3% dispose of their food waste through home composting (Ramukhwatho, 2016).

A study in Kimberley (Cronje et al., 2018) revealed that 30% of respondents plan meals in advance and only 54% of those planning their meals in advance stick to their planning. More than half (52%) of respondents indicated that they bought more food than they need. The reported reasons for buying in excess (in order of importance) are: food was marked down or on special offer (68%); impulsive purchases (15%); incomplete shopping lists (14%); and influenced by a co-shopper (3%). Further findings from this study indicate that 61% of respondents discard excess food, 25% freeze surplus food, 12% donate the food, 1% dispose of the food to home composting, and another 1% store the food in the fridge for consumption on the following day. Only 21% of respondents reported that they use leftover food in additional meals. It is encouraging that 43% of respondents indicated that it bothered them a great deal when food is thrown away. The most wasted food as reported in this study is indicated in Table 13.3 (Cronje et al., 2018).

In a provincial study in the Gauteng Province, covering 1,250 households through an electronic survey, respondents rated their food wastage as more than 20% of their monthly fresh produce purchases (Marx-Pienaar et al., 2016). The reported drivers for food wastage were similar to those reported in the UK (Marx-Pienaar et al., 2016).

Chakona and Shackleton (2017) quantified food waste along a rural-urban continuum in Richards Bay, Dundee and Harrismith. A total of554 households (183 in Richards Bay, 173 in Dundee and 198 in Harrismith) participated in the study through interviews. The majority of households are reported to eat meals as a family together at home. The findings of this study suggest that more households discard prepared food than uncooked food and drinks, but the quantities of discarded uncooked foods are significantly higher than cooked food. The estimated food waste in this study is reported to be 5-10 kg per person per annum (Chakona and Shackleton, 2017).

Table 13.3 Most wasted food items by households (% respondents) in Kimberley

Fruit

%

Vegetables

%

Other food

%

Bananas

42

T omatoes

27

Leftovers

34

Apples

20

Potatoes

17

Milk and dairy products

30

Avocado

8

Cabbage

13

Bread

25

Oranges

5

Lettuce

12

Condiments

3

Pears

4%

Carrots

9

Convenience food

3

Venter (2017) investigated Gauteng consumers’ fresh produce waste practices with a view to determining the reasons for household food wastage. The commodities wasted in order from most to least wasted are vegetables, fruit, bread, dairy products, cakes and pastries, desserts, condiments, cereals, meat, oils, beverages and sweets. The self-reported wastage as a percentage of purchase are summarised in Table 13.4. It should however be noted that the results are not representative of the demographics of the population in Gauteng (Venter, 2017).

The vegetables that are most likely to be wasted, in order from most to least, are reported as green leafy vegetables (spinach, lettuce, salad greens) followed by cucumbers, tomatoes, cabbage (cauliflower, broccoli, kale), peppers, stem and cap vegetables (mushrooms, asparagus), roots, pumpkin, peas and beans, and lastly mielie/sweetcorn on the cob. The fruits that are reportedly most likely to be wasted, in order from most to least, are soft tropical fruits (bananas, papaya, figs, guavas), hard fruit (apples and pears), avocado, melons (spanspek, watermelon), stone fruit (peaches and plums), citrus fruit, pineapple, berries and grapes. (Venter, 2017).

Universities

Food waste composition, alongside student views and behaviours have been measured at three of South Africa’s universities: Stellenbosch University (Marais et al., 2017), University of Johannesburg (Sebola et ah, 2014) and Rhodes University (Painter et ah, 2016).

Food wastage in hospitals

Nemathaga et ah (2008) did a study on waste management practices at two hospitals in the Limpopo Province of South Africa. At the time of measurement, Tshilindzini hospital had 450 admitted patients and Elim hospital 250. The leftover food recorded at the two facilities were 70 and 48 kg/day, respectively (Nemathaga et ah, 2008). This equates to 0.192 and 0.156 kg/patient per day. The reported waste management practice for leftover food is reuse or recycling, but no further detail is provided.

Table 13.4 Self-reported food waste as a percentage of purchase (N = 1,154)

Food category

% of purchase that is wasted

Vegetables

21.10

Fruit

20.14

Bread

19.22

Dairy

14.22

Cakes and pastries

13.70

Desserts

12.64

Condiments

10.55

Cereals

10.24

Meat

9.58

Oils

8.93

Beverages

8.23

Sweets

7.80

Food waste management in the hospitality sector

Mabaso (2017) conducted research on the current status of food waste management in the hospitality sector with a specific focus on an international hotel group. The research objectives covered the food waste behaviour and perceptions of hotel staff linked to food waste, and an analysis of the food waste management practices. Food waste production was measured over a six-week period. Plate waste was identified as the most common food waste, followed by production waste and serving waste. The buffet service style was identified as the service style creating the most food waste, followed by staff meals, functions, a la carte, and the hotel room service.

Marx-Pienaar et al. (2018) found that production, distribution and packaging, specifically secondary packaging used in distribution, in the quick sendee restaurant supply chain in South Africa warrants attention to reduce food waste. The specific concern regarding the secondary packaging is that even good quality secondary packaging does not provide the required protection to the food products, especially baker)' products, during transport and distribution.

Biomass waste from food production

Oelofse and Muswema (2018) estimated the waste biomass from food processing for a number of commodities as summarised in Table 13.5. The assumptions used in the calculations were sourced from international literature and applied to available statistics on production and processing of the different commodities (Oelofse and Muswema 2018).

Environmental footprint of food waste

Mekonnen and Hoekstra determined the South African water footprint, and agriculture contributed 76% of the total footprint (Mekonnen and Hoekstra, 2011). In 2014, Oelofse calculated the water footprint of food waste (excluding fish) in South Africa using the food waste estimate of Nahman and De Lange (2013). The calculated water footprint of food waste is in the order of 12,854 Mm' or the equivalent of nearly 22% of the total water footprint of agricultural production in South Africa (Oelofse, 2014).

Notten et al. (2014) estimated a ballpark figure of R1 billion per year for the cost of embedded energy wasted when food is discarded. The magnitude of this wasted energy is estimated to

Table 13.5 Summary of waste biomass from food processing identified in South Africa

Source

Assumptions

Tonnes (2012/ 13)

Malting barley

14 to 20 kg of spent grain is produced per hectolitre of beer

584,125 to 607,490

Deciduous fruit

  • 40% of input by weight - juice production
  • 17.5% of input by weight - processing for preservation

184,290

Subtropical fruit

17.5% of input by weight - processing for preservation

22,980

Citrus fruit

Peels (50% of wet juiced fruit)

224,182

Vegetables (excl. potatoes)

17.5% of input by weight - processing

32,278

Potatoes

90 kg per tonne of input (56% of this is potato skins, 33% starch and 11 % inert material)

33,427

be enough to power the City of Johannesburg for 16 years. Fruit and vegetables account for 44% of the food waste but only 15% of the cost of wasted energy. The water (ground and surface water) used to produce food that is not consumed is estimated as 1.7 km3 (Notten et al., 2014). This is equivalent to about 20% of the total water abstraction in South Africa at a cost of R260 million, with fruit and vegetables accounting for the largest portion. Food wastage therefore comes at a very high cost when considering the cost of energy, water and waste disposal. In addition, disposal of food waste to landfill adds opportunity cost that is lost when the valuable resources (energy, enzymes, etc.) locked in food waste are not utilised (Notten et al., 2014).

Governance issues

Harduth (2017) identified the need for legal protection for donors of surplus food in South Africa. She argues that surplus food is wasted due to potential donors’ fear that they may be held liable if the donated food caused harm to beneficiaries of the donated food. It is therefore proposed that South African legislation, in line with international best practice as seen in Panama, Canada, France, Italy and the United States of America, should be developed to support and encourage surplus food donations while providing the requisite protection to the donors.

 
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