Despite the potential benefits derived from fruit juice consumption, safety and quality of these juices have become of concern in both industrially processed and locally produced juices. Fruits are prone to contamination during harvesting and transportation. Also, during fruits juices processing, additional contamination may occur since they move through a series of handling and preparation before reaching the consumer. Hence, fruit juices have recently been identified as “emerging vehicles” for foodborne illnesses caused by bacterial pathogens (Dewanti-Hariyadi, 2013; Lima Tribst et al., 2009).
Results from the current study showed that all the industrially processed fruit juice samples were devoid of both E. coli and Salmonella spp. unlike the locally processed fruit juice that recorded microbial load for both microorganisms. The two bacterial genera enumerated has been identified as the leading cause of foodborne diseases (Hendriksen et al., 2011; Fratamico & Smith, 2006). The results of the industrially processed samples are consistent with Addo et al., (2008) that recorded an absence of Salmonella and any other coliform in imported fruit juice samples and similar to a report by Rahman et al., (2011) where total viable bacterial count was found to be greater in most fresh juices than in commercially packed juices. It was attributed to the fact that these juices are pasteurised and well packaged which limits E. coli and Salmonella spp. contamination. Also, the industrially produce fruit juices might have been processed under sanitary conditions and with clean water adhere to standards of regulatory institution. For the locally processed samples, E. coli was detected in 22(88%) samples but absent in only 3(12%) of the samples. Also, Salmonella was present in 10(40%) samples but absent in 15(60%) of the samples. Per the study, the data indicates that, locally produced fruit juices in Tamale are contaminated with E. coli (88%) followed by Salmonella (40%). These findings contradict Addo et al., (2008) where all freshly prepared fruit juice samples tested negative for E. coli. However, it is in line with Jesús et al., (2021) who recorded the presence of E. coli and Salmonella in 85% of fresh orange juice samples as well as Wedajo & Kadire, (2019) where 81.25% of all fresh juice samples contained E. coli and 62.5% contained Salmonella.
The microbial load for E. coli ranged from 1.3x104 cfu/ml - 9.23x104 cfu/ml and that of Salmonella was also within the range 1.0x103 cfu/ml - 9.35x105 cfu/ml (Refer to Table 2). The values obtained show that the levels were above the acceptable limits of 1x102 cfu/ml specified by the Ghana Standard Authority – GS724: 2003 and GS168: 2005 (GSA, 2003; GSA 2005).
The microorganisms found in this study were previously found in fruit by Eni et al., (2010) in his research in Nigeria and in commercially packed and fresh fruit juices in Dhaka by Rahman et al., (2011). The variation in the microbial load of these ready-to-drink fruit juices could imply how fruits are handled by specific vendors/processors and has a substantial impact on the level of microbial contamination (Eni et al., 2010). Pollutants from soil, irrigation water, the environment during transit, washing/rinsing water, or processor handling could all be factors in the bacteria found in this study (Ofor et al., 2009).
The presence of both E. coli and Salmonella could also be attributed to poor hygienic conditions and as well as source of water used for the fruit juice preparation and probably the lack of pasteurisation of the locally processed fruit juices. Artés & Allende, (2014) affirmed that one of the most common causes of fruit juice contamination is lack of pasteurization. Also, pathogens can be elevated in prepared juices due to lack of understanding about safe fruit juice production as well as contamination sources (Tasnim et al., 2010). Interestingly, it worth nothing that although sample 5 and 9, were obtained from the same vendor, peharps under same processing conditions, Sample 9, Tamarinda-ginger was devoid of both microbes. This perhaps could be attributed to possible antibacterial property of the mix. This is in agreement with Paz et al., (2015) where the widest antibacterial spectrum was found in tamarind pulp extracts, which inhibited the proliferation of all microbes tested, both Gram positive and Gram negative.
To enhance crop yields, the agricultural business (including crop cultivation and livestock production) faces hurdles. As a result, the use of antibiotics in livestock and antimicrobials on some disease-causing bacteria in fruit trees, are now common. For example, in countries where it is legal, streptomycin is applied to apple trees during bloom to prevent fire blight, with 0–4 applications per season based on disease forecast (Expert Panel on Antibiotic Resistance, 2005).
In this study, antimicrobial residues were absent in all 28 samples examined. Antibiotic residues have been linked to the usage of antimicrobial residue-contaminated manure in a number of studies (Phares et al., 2020; Quaik et al., 2020). According to Kumar et al., (2005), organic crops are likely to be infected with antibiotics due to exposure to antibiotic residues found in manure. Taylor and Reeder (2020) discovered no evidence of antibiotic use on crop plants in Africa, including Ghana.
According to the Phares et al., (2020) study, 84.2% of poultry and cattle farmers obtain antibiotics without a veterinarian's prescription, which could lead to antibiotic abuse that enters the food supply chain. Farmers may have unknowingly introduced antibiotics into the environment by using poultry droppings and dung on agricultural areas, especially when the antibiotic withdrawal time is not followed, and this can make its way into the food value chain. The recent investigation found no antimicrobial residues in any of the 28 fruit juices, which could be because the manure used on the farmland where the fruits were grown is likely to be antimicrobial residue-free, or that the antibiotic withdrawal periods were followed. Perhaps the farmers did not use any manure on their farm. Another possibility is the water used for irrigation may have not been polluted with antimicrobial residues. Since, antimicrobial residues from antibiotics can seep into water bodies when exposed to the environment, according to Amarasiri et al. (2020) wether from veterinary or other sources.