## 3 Results  
### Effect of HPP on Aerobic and Anaerobic Spores  
Total aerobic bacteria (TAB) were determined in cauliflower before and after processing and storage (Table 1). Pressurization of cauliflower at 600 MPa for 2 and 5 min reduced TAB by 2.0 and 2.3 log cfu/g, respectively, on day 14. HPP at 400 MPa for 2 and 5 min yielded low counts until day 7, but high counts on day 14 (6.4 and 6.1 log cfu/g, respectively). The non-treated samples (control) showed bacterial counts of 5.0 log cfu/g on day 0. The HPP holding time did not significantly (\(p>0.05\)) change the bacterial counts on all days (except 400 MPa day 0), indicating that shorter processing times could be beneficial. Throughout storage, and especially at the end of the storage period, a larger deviation between the samples was found. Some individual 600 MPa samples had no detectable growth at day 42, whereas others had high counts. The pressure of 600 MPa had a significant (\(p>0.05\)) effect on TAB. The increase in TAB could be due to the growth of surviving cells, in addition to recovery of injured cells. The HPP samples had an acidic smell after day 28, indicating possible lactic acid bacteria present. Vegetables have a low buffering capacity, which makes anaerobic conditions favorable for lactic acid bacteria to grow [27]. Measurements of the pH during storage could also indicate spoilage. [PERSON] et al. investigated the effects of pressure on _Lactobacillus plantarum_ in beer, a possible spoilage bacterium, and found that at pressures of 600 MPa, all cells were killed during pressure and the fraction of barotolerant cells was at or below the detection level (120 cfu/mL). They concluded that the use of HPP was effective in preventing or delaying the growth of spoilage bacteria in beer, instead of using sterilization at high temperature [28]. The carbohydrate content of cauliflower could contribute to some protection from pressure in bacteria [29]. Few studies have been conducted on the effects of HPP on the shelf life of cauliflower, and none during storage for 42 days. Among the few, [PERSON] et al. (1999) looked at the effects of HPP of cauliflower (300, 350, 400 MPa/30 min/5 \({}^{\circ}\)C) on different microbes [30]. They found low counts (below the detection limit) of TAB at 400 MPa immediately after processing. However, they processed their cauliflower in homogenized pieces in peptone water. This is different from whole pieces, and concerning the long processing conditions, comparison of their results is difficult. [PERSON] et al. performed HPP of tomato and salad greens (100-400 MPa/10 min/20 \({}^{\circ}\)C or 20 min/10 \({}^{\circ}\)C) [22]. The results showed that a pressure of 350 MPa was needed to reduce the amount of molds and most Gram-negative bacteria. At 400 MPa there were still some surviving Gram-positive bacteria, and pressurizing at 400 MPa had little effect on spores of Gram-positive bacteria. Bacterial spores represent a hazard for the food industry when they germinate and grow in food, which can lead to food poisoning and spoilage [31]. For both aerobic and anaerobic spores, low growth was detected for all samples at all stages during the storage period (Table 2). No spores were detected at day 0 of the control sample. The presence of aerobic and anaerobic spores was also checked on day 35 and 42 for HPP samples. For HPP, no significant differences were found either within or between treatments and days (\(p>0.05\)), and most counts were close to the detection limit. Even low numbers of spores can pose a threat to food safety. With the right conditions, the spores present in cauliflower could germinate and cause food poisoning. It is therefore of utmost importance to apply more specific methods to detect viable spores after processing.