LCA Food 2012 in Saint Malo, France! - Manifestations et colloques ...

PARALLEL SESSION 7C: FOOD CHAIN AND FOOD WASTE 8 th Int. Conference on LCA in the
Agri-Food Sector, 1-4 Oct 2012
entries for each time food was disposed of, where the respondents entered not only the weight and type of
food disposed of, but also the reason for disposal, such as ’spoiled’; ‘past best-before date’, etc. Diary entries
were easy to make under headings such as ’bread’, ’potato and potato products’, ’home cooked food’, and
’convenience food’, so that the respondent needed only to tick the corresponding box in the form. More detailed
description of demographic factors is presented in Silvennoinen et al., (2011).
We studied the influences of several socio-demographical, behavioural, and attitudinal factors on generating
food waste. Initially we studied the data collected through the background questionnaire, covering the
influences of all the socio-demographical, behavioural, and attitudinal factors that we expected to influence
the amount of avoidable food waste, based on our assumptions and previously published food waste studies.
Subsequently we analysed the influence of several other factors, for which we had collected data, in order to
establish whether we could identify some further, more unexpected correlations. To begin with, we analysed
most of the data using descriptive statistics, crosstabs, and histograms. Afterwards we applied a linear regression
model to the most promising factors to establish statistical significance of results. We formed dichotomous
variables to include qualitative information into the model. We also formed dummy variables, so
that we could perform regression analysis using a categorical (ordinal and nominal) variable with more than
two categories. In addition, for some of the most interesting variants that stood out in the statistical tests, we
performed one sample t-tests on the dummy variables (Koivupuro et al., 2011).
2.2 Food services data collection and analysis
Two communal food services and a company responsible for catering for the restaurants of Helsinki University
were partners in the study. The three companies had a total of 55 outlets, providing meals for various
daycare centres, schools, hospitals, elderly service centres, and workplace restaurants and canteens. The
study time for food services lasted one week.
Other restaurant and catering businesses, such as diners, restaurants, hotels, cafes, petrol stations and
similar establishments serving meals, participated during a shorter, one-day research period. In total the
study covered 17 such businesses and there were 72 participating restaurants. The total number of research
days was 292. Most of the outlets were schools and daycare centres (see Silvennoinen et al., 2012a).
In restaurants, diners and food outlets the food waste was measured by establishing the amount of food
served, and weighing waste generated during cooking and serving, and customer leftovers. All restaurants
participating in the study sorted and weighed leftovers. For communal food services the study was generally
carried out at lunch-time, with the exception of elderly service centres and hospitals where dinner was considered.
In cafes, petrol stations, diners and restaurants the whole day was usually covered. After the restaurants
closed, either the restaurant personnel or the researchers weighed the sorted waste. In addition, the personnel
completed forms with daily amounts of food prepared, and amounts of food waste from cooking,
service, and leftovers.
Furthermore, the researchers studied the leftover content over 33 days in various outlets, establishing the
composition and quantity of leftovers. Of the liquid foodstuffs, we included milk and sour milk used in the
kitchen and served to the customers, but only milk was separated from leftovers. As the amount of waste
food was compared to the amount of food cooked, all cooked food was weighed during the study period. The
personnel in restaurants and food service locations were briefed and instructed on how to define food waste
and sort leftovers so that avoidable food waste could be measured. The restaurants were provided with the
necessary forms, containers for various types of food waste, boards with guidelines for sorting food waste,
and several scales for weighing the produced food and food waste. A detailed description of data collection
is reported by Silvennoinen et al., (2012a, 2012b).
2.3. Food waste in the retail sector and industry
The data collection for food waste in the retail sector was done in cooperation with the Nordic Council’s
Retail food waste project. The project was carried out by interviewing various parties in retail chains, waste
management, and other associated actors in Sweden, Norway, Denmark and Finland. In Finland we interviewed
four retail chain representatives (covering 90% of food markets), one waste management representative
(Helsinki Region Environmental Services Authority) and a member of The Finnish Grocery Trade Association.
The research did not include any weighing to determine the actual amount of waste, and consequently
there are no public statistical data available (Stenmark et al., 2011).
The food waste data from the food industry were collected mainly from Finnish food companies that participated
in the study, and from the literature and some corporate responsibility reports. These data were col-
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