Effects of container type and size on thermal processing characteristics and B-vitamin retention of canned cat food.

Introduction: Rigid cans were the traditional container for canned cat foods, but semi-rigid trays/tubs and flexible pouches are popular options as well. Despite this, little is published on the effects of canned cat food container characteristics on thermal processing and retention of B-vitamins. Therefore, the objective was to evaluate the effects of container size and type on thermal processing and B-vitamin retention. Materials and methods: Treatments were arranged in a factorial with two container sizes [small (85-99 g) and medium (156-198 g)] and three container types (flexible, semi-rigid, and rigid). A canned cat food formula was prepared, filled, and sealed into containers before retort processing to a heating cycle target lethality of 8 min. Internal retort and container temperatures were used to calculate accumulated lethality. Thiamin, riboflavin, niacin, pantothenic acid, pyridoxine, biotin, folic acid, cobalamin, and moisture contents were analyzed in pre- and post-retort samples by commercial laboratories. Thermal processing metrics were analyzed (SAS v. 9.4; SAS Institute, Cary, NC) with the fixed effects of container size, container type, and their interaction. Dry matter basis B-vitamin contents were analyzed with container size, container type, processing stage, and all two-way and three-way interactions as fixed effects. Means were separated using Fisher's LSD at a P-value < 0.05. Results and discussion: Total accumulated lethality was greater (P < 0.05) for semi-rigid and flexible containers (average 14.99 min) than for rigid containers (12.86 min). The greater processing of semi-rigid and flexible containers was likely influenced by required retort settings. Thiamin and riboflavin contents decreased (P < 0.05) by 30.4 and 18.3%, respectively, due to retort processing. Niacin, biotin, and cobalamin were not affected (P > 0.05) by processing. Processing increased (P < 0.05) pantothenic acid (9.1%), pyridoxine (22.6%), and folic acid (22.6%). This was likely caused by sampling or analytical variation. No interaction involving processing stage was significant for any B-vitamin (P > 0.05). B-vitamin retention was not influenced by differences in thermal processing caused by the packaging treatments. Thiamin and riboflavin were the only B-vitamins meaningfully impacted by processing and retention was not improved by any container characteristic.

Impacts of vitamin premix and/or yeast ingredient inclusion in a canned cat food on thiamin retention during 6 months of storage.

Introduction: Low thiamin levels in thermally processed canned cat foods are concerning for the pet food industry. However, there is little information on storage stability of thiamin in this food format or if inclusion of select ingredients, such as dried yeasts, has an effect. Therefore, the objective was to evaluate the storage stability of thiamin when a vitamin premix and/or yeasts ingredients were included in a canned cat food. Materials and methods: The factorial treatment arrangement consisted of 2 levels of vitamin premix (with or without) and 4 inclusions of yeast (NY = none, LBV = Lalmin B Complex Vitamins, BY = product #1064B, or EA = BGYADVANTAGE). Diets were stored for 6 months and analyzed every month for thiamin. Data were analyzed as a mixed model (SAS v. 9.4; SAS Institute, Cary, NC) with fixed effects (vitamin premix, yeast, time, and their two-way and three-way interactions) and random effects (production day and the interaction of production day, vitamin premix, and yeast). Significance was set at P < 0.05 and Fisher's LSD was used to separate means. Results and discussion: Diets including the vitamin premix [average 55.1 mg/kg dry matter basis (DMB)] contained more (P < 0.05) thiamin than diets that did not (average 7.5 mg/kg DMB). Inclusion of LBV (average 40.3 mg/kg DMB) resulted in the highest (P < 0.05) levels of thiamin, followed by BY (P < 0.05; average 26.9 mg/kg DMB). Diets with NY and EA contained the lowest (P < 0.05) levels of thiamin and were not different from each other (P > 0.05; average 19.3 mg/kg DMB). The diet containing vitamin premix without yeast lost (P < 0.05) 17.8% thiamin while diets containing a yeast ingredient maintained thiamin levels better during storage. This suggested that thiamin from yeast ingredients was more resistant to degradation during storage and should be considered when designing new canned cat foods.

Composition and thermal processing evaluation of yeast ingredients as thiamin sources compared to a standard vitamin premix for canned cat food.

Significant improvement in thiamin retention of canned cat food has not been achieved by altering processing conditions. Some ingredients, such as yeasts, may supply thiamin able to withstand thermal processing. Therefore, the study objective was to evaluate yeast ingredients as thiamin sources for canned cat food. Six yeast ingredients were screened for thiamin content, and values ranged from 9.9-4,283.8 mg/kg dry matter basis (DMB). Treatments for thermal processing were arranged as a 2×4 factorial with 2 levels of vitamin premix (with or without) and 4 yeast ingredients (NY = none and LBV, BY, or EA from the ingredient screening). Replicates (n = 3) were processed in a horizontal still retort to an average lethality of 79.23 minutes. Thiamin degradation was analyzed as a mixed model with pre-retort thiamin content as a covariate and production day as a random effect. Main effects of vitamin premix and yeast and their interaction were significant at P-values less than 0.05. The Fisher's LSD post hoc comparison test was used to separate means. On average, experimental formulas retained 33.75% thiamin. The main effect of vitamin premix (average -42.9 mg/kg DMB) was not significant (P > 0.05). Thiamin degradation between NY (-31.3 mg/kg DMB) and BY (-33.8 mg/kg DMB) was similar (P > 0.05) whereas EA (-40.5 mg/kg DMB) and LBV (-55.6 mg/kg DMB) lost more (P < 0.05) thiamin than NY. The experimental formula of EA with vitamin premix (-70.3 mg/kg DMB) lost more (P < 0.05) thiamin than no yeast, BY, or EA without vitamin premix (average -17.4 mg/kg DMB) and all others (average -57.3 mg/kg DMB) were intermediate (P > 0.05). In summary, thiamin from yeast ingredients didn't exhibit better thermal stability than thiamin mononitrate. However, those ingredients with similar degradation levels or uniquely high thiamin levels may provide added value.

Effects of select copper sources at minimum supplementation levels on nutrient content, off-colors, and blemishes in canned pet food.

In the previous research, super-fortification with copper decreased vitamin E content and darkened canned pet food, which prevented the analysis of black blemishes reported in commercial products. The pet food industry has linked these blemishes, which may be concerning to pet owners, to copper supplementation. The objective of this study was to determine the effect of different copper sources included at minimum recommended levels on nutrient content, color, and blemishes in canned pet food. Treatments were arranged in a 2 × 3 + 1 factorial, with 2 levels of copper supplementation [6 and 12 mg/kg dry matter (DM)], 3 copper sources (CG = copper glutamate, CA = copper amino acid complex, and CS = copper sulfate), and a control with no added copper (NC). Diets were analyzed for macronutrients (moisture, crude protein, crude fat, crude fiber, and ash) and micronutrients (calcium, phosphorus, potassium, sodium, magnesium, sulfur, iron, copper, manganese, zinc, and vitamin E). Color was quantified with a CIELAB color space colorimeter wherein L* values closer to 100 represented lighter products and more positive a* and b* values indicated redder and yellower products, respectively. Blemishes were enumerated and their surface area quantified with ImageJ software. Data were analyzed as a general linear mixed model with the fixed effect of treatment and the random effect of production day. P-values less than 0.05 were considered significant. The 12 mg/kg DM treatments (average 14.19 mg/kg DM) contained the highest (P < 0.05) level of copper, followed by 6 mg/kg DM treatments (average 7.59 mg/kg DM) and then NC (0.00 mg/kg DM). Addition of copper decreased (P < 0.05) vitamin E content, except for NC and CS12 which were similar (P > 0.05; average 111.89 mg/kg DM). Lightness (average L* 63.66) was not affected (P > 0.05) by the treatments. Adding copper decreased (P < 0.05) redness, with higher (P < 0.05) a* values for CG6 (9.55) vs. CA6 and CS6 (average 8.50). Yellowness also decreased with the addition of copper, except for CG6 which was similar (P > 0.05) to NC (average 18.70). However, CG6 and CG12 (average 4.05 blemishes/slice of food) contained more (P < 0.05) blemishes than CA6, CS6, and CS12 (average 0.97 blemishes/slice of food). Minimal levels of supplemental copper from CG may enhance overall color preservation but could increase blemish occurrence. No disadvantage was observed for CA vs. CS, indicating that CA could be exchanged for CS in formulations.

Nutritional and physico-chemical implications of avocado meal as a novel dietary fiber source in an extruded canine diet.

This study assessed the effects of a diet containing avocado meal (AMD), an underutilized by-product avocado oil processing, on apparent total tract digestibility (ATTD) and fecal fermentative end-products when compared with beet pulp (BPD) and cellulose (CD) diets targeting 15% total dietary fiber (TDF). The concentration of persin, a natural fungicidal toxin present in avocado, was also determined on several parts of the fruit and avocado meal. Nine intact female beagles (4.9 ± 0.6 yr and 11.98 ± 1.76 kg) were randomly grouped in a 3 × 3 replicated Latin square design. Periods were 14 d long, with 10 d of adaptation followed by 4 d of total fecal and urine collection for apparent total tract digestibility (ATTD) calculations. Fresh fecals were analyzed for fermentative end-products. The BPD (87.0 g/d) caused higher (P < 0.05) fecal output (as-is basis) than AMD (62.3 g/d) and CD (58.0 g/d). Fecal score for the BPD (3.1) was greater (P < 0.05) than for AMD (2.8) or CD (2.6). Acid-hydrolyzed fat ATTD was lower (P < 0.05) for the BPD (94.1%) than for the AMD (95.5%) and CD (95.7%). Crude protein ATTD was greater (P < 0.05) for the CD (88.5%) than the AMD (82.2%) or BPD (83.7%). Dogs fed AMD (49.9%) or BPD (51.0%) exhibited greater (P < 0.05) TDF ATTD than CD. The fermentative profile for the AMD (233.4, 70.9, 8.8, and 12.0 µmole/g DM, respectively) was similar (P > 0.05) to the CD (132.9, 61.7, 7.5, and 9.5 µmole/g DM, respectively) profile, with lower (P < 0.05) concentrations of acetate and propionate and higher (P < 0.05) concentrations of isovalerate and indoles compared to the BPD. Dogs fed AMD (47.0 µmole/g DM) or BPD (54.2 µmole/g DM) exhibited similar (P > 0.05) fecal butyrate concentrations greater (P < 0.05) than for CD (24.7 µmole/g DM). Given these results, avocado meal appears to be an adequate dietary fiber source when compared with traditional fiber sources used in canine diets. No health adverse effects were observed in dogs fed extruded diet containing as much as 18% of avocado meal (as-is basis).

A review: nutrition and process attributes of corn in pet foods.

Corn is one of the largest cereal crops worldwide and plays an important role in the U.S. economy. The pet food market is growing every year, and although corn is well utilized by dogs, some marketing claims have attributed a negative image to this cereal. Thus, the objective of this work was to review the literature regarding corn and its co-products, as well as describe the processing of these ingredients as they pertain to pet foods. Corn is well digested by both dogs and cats and provides nutrients. The processing of corn generates co-products such as corn gluten meal and distillers dried grains with solubles that retain quality protein, and fibrous components that dilute dietary energy. Further, corn has much functionality in extrusion processing. It may yield resistant starch under certain processing conditions, promoting colonic health. Carotenoids in corn may enhance immune support in companion animals if concentrated. Mycotoxin contamination in grains represent a health hazard but are well controlled by safety measures. Genetically modified (GM) corn is still controversial regarding its long-term potential for mutagenicity or carcinogenicity, thus more long-term studies are needed. In conclusion, the negative perception by some in the pet food market may not be warranted in pet foods using corn and its co-products.

The Effects of Select Hydrocolloids on the Processing of Pâté-Style Canned Pet Food.

Hydrocolloids are commonly used in canned pet food. However, their functional effects have not been quantified in this food format. The objective was to determine the effects of select hydrocolloids on batter consistency, heat penetration, and texture of canned pet food. Treatments were added to the formula as 1% dextrose (D) and 0.5% guar gum with 0.5% of either dextrose (DG), kappa carrageenan (KCG), locust bean gum (LBG), or xanthan gum (XGG). Data were analyzed as a 1-way ANOVA with batch as a random effect and separated by Fisher's LSD at p < 0.05. Batter consistency (distance traveled in 30 s) thickened with increasing levels of hydrocolloids (thinnest to thickest: 23.63 to 2.75 cm). The D treatment (12.08 min) accumulated greater lethality during the heating cycle compared to all others (average 9.09 min). The KCG treatment (27.00 N) was the firmest and D and DG (average 8.75 N) the softest with LBG and XGG (average 15.59 N) intermediate. Toughness was similar except D (67 N·mm) was less tough than DG (117 N·mm). The D treatment showed the greatest expressible moisture (49.91%), LBG and XGG the lowest (average 16.54%), and DG and KCG intermediate (average 25.26%). Hydrocolloids influenced heat penetration, likely due to differences in batter consistency, and affected finished product texture.

Sustainability and Pet Food: Is There a Role for Veterinarians?

Sustainability has become a watchword for a wide array of resource-intensive goods and services. This is promulgated by an increasing global population and concerns that natural resources and a hospitable climate will not be preserved for future generations. Life-cycle analysis is a tool that provides a framework to determine the magnitude products contribute to carbon emissions and depletion of natural resources. In this review, published research has been summarized to provide an overview of the impacts that pet food production and pet ownership have on the environment and the prospective role of veterinary practitioners in advocating for sustainability.